Category Archives: Quantum Computing

New silicon structure opens the gate to quantum computers

In a major step toward making a quantum computer using everyday materials, a team led by researchers at Princeton University has constructed a key piece of silicon hardware capable of controlling quantum behavior between two electrons with extremely high precision. The study was published Dec. 7 in the journal Science.

The team constructed a gate that controls interactions between the electrons in a way that allows them to act as the quantum bits of information, or qubits, necessary for quantum computing. The demonstration of this nearly error-free, two-qubit gate is an important early step in building a more complex quantum computing device from silicon, the same material used in conventional computers and smartphones.

“We knew we needed to get this experiment to work if silicon-based technology was going to have a future in terms of scaling up and building a quantum computer,” said Jason Petta, a professor of physics at Princeton University. “The creation of this high-fidelity two-qubit gate opens the door to larger scale experiments.”

Silicon-based devices are likely to be less expensive and easier to manufacture than other technologies for achieving a quantum computer. Although other research groups and companies have announced quantum devices containing 50 or more qubits, those systems require exotic materials such as superconductors or charged atoms held in place by lasers.

Quantum computers can solve problems that are inaccessible with conventional computers. The devices may be able to factor extremely large numbers or find the optimal solutions for complex problems. They could also help researchers understand the physical properties of extremely small particles such as atoms and molecules, leading to advances in areas such as materials science and drug discovery.

The two-qubit silicon-based gate consists of two electrons (blue balls with arrows) in a layer of silicon (Si). By applying voltages through aluminum oxide (Al2O3)wires (red and green), the researchers trapped the electrons and coaxed quantum behaviors that transform their spin properties into quantum bits of information, or qubits. The image on the left shows a scanning electron micrograph of the device, which is about 200 nanometers (nm) across. The image on the right is a diagram of the device from the side.

Image courtesy of Science/AAAS

Building a quantum computer requires researchers to create qubits and couple them to each other with high fidelity. Silicon-based quantum devices use a quantum property of electrons called “spin” to encode information. The spin can point either up or down in a manner analogous to the north and south poles of a magnet. In contrast, conventional computers work by manipulating the electron’s negative charge.

Achieving a high-performance, spin-based quantum device has been hampered by the fragility of spin states they readily flip from up to down or vice versa unless they can be isolated in a very pure environment. By building the silicon quantum devices in Princeton’s Quantum Device Nanofabrication Laboratory, the researchers were able to keep the spins coherent that is, in their quantum states for relatively long periods of time.

To construct the two-qubit gate, the researchers layered tiny aluminum wires onto a highly ordered silicon crystal. The wires deliver voltages that trap two single electrons, separated by an energy barrier, in a well-like structure called a double quantum dot.

By temporarily lowering the energy barrier, the researchers allow the electrons to share quantum information, creating a special quantum state called entanglement. These trapped and entangled electrons are now ready for use as qubits, which are like conventional computer bits but with superpowers: while a conventional bit can represent a zero or a 1, each qubit can be simultaneously a zero and a 1, greatly expanding the number of possible permutations that can be compared instantaneously.

“The challenge is that its very difficult to build artificial structures small enough to trap and control single electrons without destroying their long storage times,” said David Zajac, a graduate student in physics at Princeton and first-author on the study. “This is the first demonstration of entanglement between two electron spins in silicon, a material known for providing one of the cleanest environments for electron spin states.”

The researchers demonstrated that they can use the first qubit to control the second qubit, signifying that the structure functioned as a controlled NOT (CNOT) gate, which is the quantum version of a commonly used computer circuit component. The researchers control the behavior of the first qubit by applying a magnetic field. The gate produces a result based on the state of the first qubit: If the first spin is pointed up, then the second qubit’s spin will flip, but if the first spin is down, the second one will not flip.

“The gate is basically saying it is only going to do something to one particle if the other particle is in a certain configuration,” Petta said. “What happens to one particle depends on the other particle.”

The researchers showed that they can maintain the electron spins in their quantum states with a fidelity exceeding 99 percent and that the gate works reliably to flip the spin of the second qubit about 75 percent of the time. The technology has the potential to scale to more qubits with even lower error rates, according to the researchers.

“This work stands out in a worldwide race to demonstrate the CNOT gate, a fundamental building block for quantum computation, in silicon-based qubits,” said HongWen Jiang, a professor of physics and astronomy at the University of California-Los Angeles.”The error rate for the two-qubit operation is unambiguously benchmarked. It is particularly impressive that this extraordinarily difficult experiment, which requires a sophisticated device fabrication and an exquisite control of quantum states, is done in a university lab consisting of only a few researchers.”

Additional researchers at Princeton are graduate student Felix Borjans and associate research scholar Anthony Sigillito. The team included input on the theory aspects of the work by Jacob Taylor, a professor at the Joint Quantum Institute and Joint Center for Quantum Information and Computer Science at the National Institute of Standards and Technology and the University of Maryland, and Maximilian Russ and Guido Burkard at the University of Konstanz in Germany.

Research was sponsored by U.S. Army Research Office grant W911NF-15-1-0149, the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant GBMF4535, and National Science Foundation grant DMR-1409556. Devices were fabricated in the Princeton University Quantum Device Nanofabrication Laboratory.

The study, “Resonantly driven CNOT gate for electron spins,” by David M. Zajac, Anthony J. Sigillito, Maximilian Russ, Felix Borjans, Jacob M. Taylor, Guido Burkard and Jason R. Petta was published online in the journal Science on Dec. 7, 2017.

Originally posted here:
New silicon structure opens the gate to quantum computers

Microsoft offers developers a preview of its quantum …

The simulator will allow developers to test programs and debug code with their own computers, which is necessary since there really aren’t any quantum computers for them to test their work on yet. Microsoft is also offering a more powerful simulator — one with over 40 logical qubits of computing power — through its Azure cloud computing service. And because the kit is integrated into Microsoft’s Visual Studio developer tool suite, many aspects of the new kit will be familiar.

“What you’re going to see as a developer is the opportunity to tie into tools that you already know well, services you already know well,” Todd Holmdahl, Microsoft’s VP in charge of its quantum effort, said in a statement. “There will be a twist with quantum computing, but it’s our job to make it as easy as possible for the developers who know and love us to be able to use these new tools that could potentially do some things exponentially faster which means going from a billion years on a classical computer to a couple hours on a quantum computer.”

Read more:
Microsoft offers developers a preview of its quantum …

Quantum Computing Is the Next Big Security Risk | WIRED

The 20th century gave birth to the Nuclear Age as the power of the atom was harnessed and unleashed. Today, we are on the cusp of an equally momentous and irrevocable breakthrough: the advent of computers that draw their computational capability from quantum mechanics.

US representative Will Hurd (R-Texas) (@HurdOnTheHill) chairs the Information Technology Subcommittee of the Committee on Oversight and Government Reform and serves on the Committee on Homeland Security and the Permanent Select Committee on Intelligence.

The potential benefits of mastering quantum computing, from advances in cancer research to unlocking the mysteries of the universe, are limitless.

But that same computing power can be used to unlock different kinds of secretsfrom your personal financial or health records, to corporate research projects and classified government intelligence.

Its more than just theoretical: An algorithm formulated by mathematician Peter Shor demonstrates that quantum computers are able to factor large numbers more efficiently than classical computers. Large-number factoring is the foundation of todays encryption standards.

The impact of quantum on our national defense will be tremendous. The question is whether the United States and its allies will be ready.

The consequences of mastering quantum computing, while not as visual or visceral as a mushroom cloud, are no less significant than those faced by the scientists who lit up the New Mexico sky with the detonation at the Trinity test site 72 years ago. In the same way that atomic weaponry symbolized power throughout the Cold War, quantum capability is likely to define hegemony in todays increasingly digital, interconnected global economy.

Unlike traditional computers, which process information in binary bits, quantum computers exploit the ability of quantum bits (qubits) to exist in multiple states simultaneously. This allows them to perform incredibly complex calculations at speeds unimaginable today and solve certain classes of problems that are beyond the grasp of todays most advanced super computers.

Today, quantum computers are beginning to move out of research labs in search of broader investment and applications. In October, Google announced that by the end of this year it expects to achieve quantum supremacythe point at which a quantum computer can outperform a classical computer.

Because nations around the world, including China, are investing heavily in research and development, the world is likely less than a decade away from the day when a nation-state could use quantum computers to render many of todays most sophisticated encryption systems useless.

From academics to the National Security Agency, there is widespread agreement that quantum computers will rock current security protocols that protect global financial markets and the inner workings of government.

Already, intelligence agencies around the world are archiving intercepted communications transmitted with encryption that’s currently all but unbreakable, in the hopes that in the future computing advances will turn whats gibberish now into potentially valuable intelligence. Rogue states may also be able to leverage the power of quantum to attack the banking and financial systems at the heart of western capitalism.

Everyone has seen the damage individual hackers can do when they infiltrate a system. Imagine a nation-state intercepting the encrypted financial data that flows across the globe and being able to read it as easily as you are reading this. Quantum computers are so big and expensive thatoutside of global technology companies and well-funded research universitiesmost will be owned and maintained by nation-states. That means the first quantum attacks are likely to be organized by countries hostile to the US and our allies. Rogue states could read military communiques the way the United States and its allies did after cracking the Nazi Enigma codes.

In short, quantum computing presents both an unprecedented opportunity and a serious threat. The United States must lead this transition, in collaboration with its allies around the world. Whether lawmakers want to think of it as a new Manhattan Project or a race to the moon, the US cannot abdicate leadership in scientific discovery or international security.

The window is closing, fast. It took more than five years and nearly half a trillion dollars for companies and governments to prepare for Y2K, which resulted in a non-event for most people. But, the US is not ready for what experts call Y2Q (Years to Quantum), and the time to prepare is now. Even in a pre-quantum era, the need for quantum-safe encryption is real. Banks, government agencies, insurers, hospitals, utilities, and airlines all need to be thinking now about how to implement security and encryption that will withstand a quantum attack.

On complex, large-scale networks, it can take years to roll out even a relatively straightforward update. Quantum-safe encryption relies on mathematical approaches that even quantum computers have difficulty solving. The challenge is ensuring that every point through which data flows, and even the data itself, is wrapped in quantum-safe security.

Private sector research and development are happening in pockets across North America and among the US’s allies. Google and IBM both have well-publicized programs to build viable quantum computers. At the same time, though, the US and its allies must take practical steps to prepare for the quantum threat. The National Institute of Standards and Technology is working to evaluate quantum-safe cryptographic candidate algorithms. Other organizations like the European Telecommunications Standards Institute and the United Nations International Telecommunications Union are working to ensure our standards for connecting systems continue to evolve to be quantum safe. Companies like ISARA are among a small cadre of cryptographers and programmers building quantum-safe security solutions to help high-risk industries and organizations begin protecting themselves.

Its these kinds of efforts that the US and its allies must collaborate on to align the goals of scientific discovery, technological advancement, and national security. As companies build powerful quantum machines, leaders must simultaneously understand the risks those machines pose and the counter-measures required. Executives in every industry need to understand the implications that quantum computing will have on their legacy systems, and take steps to be ready. At a minimum, that means retrofitting their networks, computers, and applications with encryption that can withstand a quantum attack.

Nowhere is it more vital to begin preparations than with the vast network of governmental systems that do everything from processing Social Security checks to analyzing vast amounts of electronic intelligence.

Whether it was the discovery of fission or the launch of Sputnik, the United States has responded to scientific challenges of the past century with resolve and determination. The US must do the same with quantum computing.

WIRED Opinion publishes pieces written by outside contributors and represents a wide range of viewpoints. Read more opinions here.

Read the original here:
Quantum Computing Is the Next Big Security Risk | WIRED

Yale Professors Race Google and IBM to the First Quantum …

Quantum computing systems are difficult to understand because they do not behave like the everyday world we live in. But this counterintuitive behavior is what allows them to perform calculations at rate that would not be possible on a typical computer.

Todays computers store information as bits, with each transistor holding either a 1 or a 0. But thanks to something called the superposition principle behavior exhibited by subatomic particles like electrons and photons, the fundamental particles of light a quantum bit, or qubit, can store a 1 and a 0 at the same time. This means two qubits can hold four values at once. As you expand the number of qubits, the machine becomes exponentially more powerful.

Todd Holmdahl, who oversees the quantum project at Microsoft, said he envisioned a quantum computer as something that could instantly find its way through a maze. A typical computer will try one path and get blocked and then try another and another and another, he said. A quantum computer can try all paths at the same time.

The trouble is that storing information in a quantum system for more than a short amount of time is very difficult, and this short coherence time leads to errors in calculations. But over the past two decades, Mr. Schoelkopf and other physicists have worked to solve this problem using what are called superconducting circuits. They have built qubits from materials that exhibit quantum properties when cooled to extremely low temperatures.

With this technique, they have shown that, every three years or so, they can improve coherence times by a factor of 10. This is known as Schoelkopfs Law, a playful ode to Moores Law, the rule that says the number of transistors on computer chips will double every two years.

Schoelkopfs Law started as a joke, but now we use it in many of our research papers, said Isaac Chuang, a professor at the Massachusetts Institute of Technology. No one expected this would be possible, but the improvement has been exponential.

These superconducting circuits have become the primary area of quantum computing research across the industry. One of Mr. Schoelkopfs former students now leads the quantum computing program at IBM. The founder of Rigetti Computing studied with Michel Devoret, one of the other Yale professors behind Quantum Circuits.

In recent months, after grabbing a team of top researchers from the University of California, Santa Barbara, Google indicated it is on the verge of using this method to build a machine that can achieve quantum supremacy when a quantum machine performs a task that would be impossible on your laptop or any other machine that obeys the laws of classical physics.

There are other areas of research that show promise. Microsoft, for example, is betting on particles known as anyons. But superconducting circuits appear likely to be the first systems that will bear real fruit.

The belief is that quantum machines will eventually analyze the interactions between physical molecules with a precision that is not possible today, something that could radically accelerate the development of new medications. Google and others also believe that these systems can significantly accelerate machine learning, the field of teaching computers to learn tasks on their own by analyzing data or experiments with certain behavior.

A quantum computer could also be able to break the encryption algorithms that guard the worlds most sensitive corporate and government data. With so much at stake, it is no surprise that so many companies are betting on this technology, including start-ups like Quantum Circuits.

The deck is stacked against the smaller players, because the big-name companies have so much more money to throw at the problem. But start-ups have their own advantages, even in such a complex and expensive area of research.

Small teams of exceptional people can do exceptional things, said Bill Coughran, who helped oversee the creation of Googles vast internet infrastructure and is now investing in Mr. Schoelkopfs company as a partner at Sequoia. I have yet to see large teams inside big companies doing anything tremendously innovative.

Though Quantum Circuits is using the same quantum method as its bigger competitors, Mr. Schoelkopf argued that his company has an edge because it is tackling the problem differently. Rather than building one large quantum machine, it is constructing a series of tiny machines that can be networked together. He said this will make it easier to correct errors in quantum calculations one of the main difficulties in building one of these complex machines.

But each of the big companies insist that they hold an advantage and each is loudly trumpeting its progress, even if a working machine is still years away.

Mr. Coughran said that he and Sequoia envision Quantum Circuits evolving into a company that can deliver quantum computing to any business or researcher that needs it. Another investor, Canaans Brendan Dickinson, said that if a company like this develops a viable quantum machine, it will become a prime acquisition target.

The promise of a large quantum computer is incredibly powerful, Mr. Dickinson said. It will solve problems we cant even imagine right now.

An earlier version of this article misstated the surname of one of the investors in Quantum Circuits. As correctly noted elsewhere in the article, he is Brendan Dickinson, not Dickson.

View post:
Yale Professors Race Google and IBM to the First Quantum …

IBM’s processor pushes quantum computing … –

Quantum computers work much differently than regular supercomputers, taking advantage of weird quantum physics principals like “superposition.” In theory, they can run specific programs, like encryption-cracking algorithms, many, many times faster than regular computers.

The 50 qubit system (shown below) is a significant leap toward practical quantum computers. “We are really proud of this, it’s a big frickin’ deal,” IBM AI and quantum computer director Dario Gil told MIT Technology Review. Other players in quantum computing including Google, Intel and Rigetti.

IBM’s 50 qubit computer is just a prototype, but it will soon have a working 20 qubit computer that users can try online by the end of 2017, with improvements planned throughout 2018. The company has already made lower-powered machines available for cloud use, and used a 7 qubit model to simulate a molecule, for example. IBM says around 60,000 users have run 1.7 million experiments, resulting in 35 research papers.

Quantum computers haven’t been able to run programs that a regular computer can’t, so the massive speed breakthrough many have hoped for has yet to arrive. Still, Google researchers said last month that a 50 qubit computer they’re working on could surpass current supercomputers, achieving an (excellently-named) milestone called Quantum Supremacy. The technology is tricky, though, so there’s good reason not to get too excited. But, there’s also a good chance that quantum computers will finally break that barrier sometime in the next year or two.

Go here to read the rest:
IBM’s processor pushes quantum computing … –

Quantum computing –

A full stackWith Mundies backing, Freedman set up a lab in Santa Barbara, California, and began recruiting some of the worlds pre-eminent condensed-matter and theoretical physicists, materials scientists, mathematicians and computer scientists to work on building the topological qubit. That team now boasts many leading quantum experts who have joined Microsoft as employees in the past year, including Leo Kouwenhoven, Charles Marcus, David Reilly and Matthias Troyer.

To create the infrastructure for a full computing platform, Microsoft has simultaneously worked on building hardware, software and programming languages for topological quantum computing.

At Ignite on Monday, Microsoft announced the latest milestone in its effort to build a full stack: A new programming language that is designed for developers to create apps to debug on quantum simulators today and run on an actual topological quantum computer in the future.

The same code that youre running today in simulation you can run tomorrow on our quantum computer, Svore said.

Svore said the new tools are designed for developers who are interested in being on the cutting-edge of computer advances the same type of people who were early adopters of machine learning and other artificial intelligence advances.

You dont have to be a quantum physicist to use them. The new programming language is deeply integrated into Visual Studio, and it includes the kinds of tools that developers rely on for classical computing, such as debugging and auto complete.

It shouldnt look too different from the things theyre already doing, Svore said.

The system, which will be available as a free preview by the end of the year, also includes libraries and tutorials so developers can familiarize themselves with quantum computing. Its designed to work at a higher level of abstraction, so that developers without quantum expertise can actually call quantum subroutines, or write sequences of programming instructions, working up to writing a complete quantum program. Developers can sign up to participate today.

The system is designed so that individual users can simulate problems that require up to 30 logical qubits of power on their own personal computers, and select enterprise customers, using Azure, can simulate more than 40 qubits of computational power.

In quantum computing, the power grows exponentially with the number of logical qubits. A logical qubit is the qubit at the level of the algorithm. At that hardware level, each logical qubit is represented in hardware by a number of physical qubits to enable protection of the logical information. Microsofts approach takes fewer topological qubits to develop one logical qubit, making it far easier to scale.

Svore said one key advantage to having a programming language that works in a simulation environment is that it will help people interested in using quantum computers to solve problems get a better sense of how to harness quantum power for different types of problems. That will accelerate their ability to take advantage of quantum computing when its available.

Read the original here:
Quantum computing –

Intel Takes First Steps To Universal Quantum Computing

October 11, 2017Timothy Prickett Morgan

Someone is going to commercialize a general purpose, universal quantum computer first, and Intel wants to be the first. So does Google. So does IBM. And D-Wave is pretty sure it already has done this, even if many academics and a slew of upstart competitors dont agree. What we can all agree on is that there is a very long road ahead in the development of quantum computing, and it will be a costly endeavor that could nonetheless help solve some intractable problems.

This week, Intel showed off the handiwork its engineers and those of partner QuTech, a quantum computing spinoff from the Technical University of Delft and Toegepast Natuurwetenschappelijk Onderzoek (TNO), which as the name suggests is an applied science research firm that, among other things, is working with Intel on quantum computing technology.

TNO, which was established in 1988, has a 500 million annual budget and does all kinds of primary research. The Netherlands has become a hotbed of quantum computing technology, along with the United States and Japan, and its government wants to keep it that way and hence the partnership in late 2015 with Intel, which invested $50 million in the QuTech partnership between TU Delft and TNO so it could jumpstart its own quantum computing program after sitting on the sidelines.

With this partnership, Intel is bringing its expertise in materials science, semiconductor manufacturing, interconnects, and digital systems to play to help develop two types of quantum bits, or qubits, which are the basic element of processing in a quantum computer. The QuTech partnership involves the manufacturing of superconducting qubits, but Intel also is working on another technology called spin qubits that makes use of more traditional semiconductor technologies to create what is, in essence, the quantum transistor for this very funky and very parallel style of computing.

The big news this week is that Intel has been able to take a qubit design that its engineers created alongside of those working at QuTech and scale it up to 17 qubits on a single package. A year ago, the Intel-QuTech partnership had only a few qubits on their initial devices, Jim Clarke, director of quantum hardware at Intel, tells The Next Platform, and two years ago it had none. So that is a pretty impressive roadmap in a world where Google is testing a 20 qubit chip and hopes to have one running at 49 qubits before the year is out. Google also has quantum annealing systems from D-Wave, which have much more scale in terms of qubits 1,000 today and 2,000 on the horizon but according to Intel are not a generic enough to be properly commercialized. And if Intel knows anything, it knows how to create a universal computing substrate and scale its manufacturing and its deployment in the datacenters of the world.

Production and cleanroom facilities for the quantum chip made at Intels D1D/D1X plant in Hillsboro, Oregon, in April 2017.

We are trying to build a general purpose, universal quantum computer, says Clarke. This is not a quantum annealer, like the D-Wave machine. There are many different types of qubits, which are the devices for quantum computing, and one of the things that sets Intel apart from the other players is that we are focused on multiple qubit types. The first is a superconducting qubit, which is similar to what Google, IBM, and a startup named Rigetti Computing are working on. But Intel is also working on spin qubits in silicon are very similar to our transistor technologies, and you can expect to hear about that in the next couple of months. These spin qubits build on our expertise in ordinary chip fabrication, and what really sets us apart here is our use of advanced packaging at very low temperatures to improve the performance of the qubit, and with an eye towards scalability.

Just as people are obsessed with the number of transistors or cores on a standard digital processor, people are becoming a bit obsessed with the number of qubits on a quantum chip, and Jim Held, director of emerging technology research at Intel Labs, says that this focus is a bit misplaced. And for those of us who look at systems for a living, this makes perfect sense. Intel is focused on getting the system design right, and then scaling it up on all vectors to build a very powerful quantum machine.

Here is the situation as Held sees it, and breathe in deeply here:

People focus on the number of qubits, but that is just one piece of what is needed. We are really approaching this as engineers, and everything is different about this kind of computer. It is not just the devices, but the control electronics and how the qubits are manipulated with microwave pulses and measured with very sensitive DC instrumentation, and it is more like an analog computer in some respects. Then it has digital electronics that do error correction because quantum devices are very fragile, and they are prone to errors and to the degree that we can correct the errors, we can compute better and longer with them. It also means a new kind of compiler in order to get the potential parallelism in an array of these qubits, and even the programs, the algorithms, written for these devices are an entirely different kind of thing from conventional digital programming. Every aspect of the stack is different. While there is research going on in the academic world at all levels, as an engineering organization we are coming at them all together because we know we have to deliver them all at once as a computer. Moreover, our experience tells us that we want to understand at any given point what our choices at one level are going to mean for the rest of the computer. What we know is that if you have a plate full of these qubits, you do not have a quantum computer, and some of the toughest problems with scaling are in the rest of the stack. Focusing on the number of qubits or the coherence time really does a disservice to the process of getting to something useful.

This is analogous to massively parallel machines that dont have enough bandwidth or low latency to talk across cores, sockets, or nodes efficiently and to share work. You can cram as many cores as you want in them, but the jobs wont finish faster.

And thus, Intel is focusing its research on the interconnects that will link qubits together on a device and across multiple devices.

The interconnects are one of the things that concerns us most with quantum computing, says Clarke. From the outset, we have not been focused on a near-term milestone, but rather on what it would take from the interconnect perspective, from the point of view of the design and the control, to deliver a large scale, universal quantum computer.

Interestingly, Clarke says that the on-chip interconnect on commercial quantum chips will be similar to that used on a conventional digital CPU, but it may not be made out of copper wires, but rather superconducting materials.

The one used in the superconducting qubit chip that Intel just fabbed in its Oregon factory and packaged in its Arizona packaging facility is a bit ridiculous looking.

Quantum computing presents a few physical challenges, and superconducting qubits are especially tricky. To keep preserve the quantum states that allow superposition a kind of multiple, concurrent state of the bits that allows for parallel processing at the bit level, to over simplify hugely requires for these analog devices to be kept at extremely cold temperatures and yet still have to interface with the control electronics in the outside world, crammed into a rack.

We are putting these chips in an extremely cold environment 20 millikelvins, and that is much colder than outer space, says Clarke. And first of all, we have to make sure that the chip doesnt fall apart at these temperatures. You have thermal coefficient of expansion. Then you need to worry about package yield and then about the individual qubit yield. Then we worry about wiring them up in a more extensible fashion. These are very high quality radio or microwave frequency chips and we have to make sure we maintain that quality at low temperature once the device is packaged. A lot of the performance and yield that we are getting comes from the packaging.

So for this chip, Intel has wallpapered one side of the chip with standard coaxial ports, like the ones on the back of your home router. Each qubit has two or more coax ports going into it to control its state and to monitor that state. How retro:

We are focused on a commercial machine, so we are much more interested in scaling issues, Held continues along this line of thinking. You have to be careful to not end up in a dead end that only gets you so far. This quantum chip interconnect is not sophisticated like Omni-Path, and it does not scale well, Held adds with a laugh. What we are interested in is improving on that to reduce the massive number of connections. A million qubits turning into millions of coax cables is obviously not going to work. Even at hundreds of qubits, this is not going to work. One way we are going to do this is to move the electronics that is going to control this quantum machine into this very cold environment, not down at the millikelvin level, but a layer or two up at the 4 kelvin temperature of liquid hydrogen. Our partners at QuTech are experts at cryo-CMOS, which means making chips work in this 4 kelvin range. By moving this control circuitry from a rack outside of the quantum computer into the refrigeration unit, it cuts the length of the connections to the qubits.

With qubits, superposition allows a single qubit to represent two different states, and quantum entanglement what Einstein called spooky action at a distance allows for the states to scale linearly as the qubit counts go up. Technically, n quantum bits yield 2 to the n states. (We wrote that out because there is something funky about superscripts in the Alike font we use here at The Next Platform.) The interconnect is not used to maintain the quantum states across the qubits that happens because of physics but to monitor the qubit states and maintain those states and, importantly, to do error correction. Qubits cant be shaken or stirred or they lose their state, and they are extremely fussy. As Google pointed out two years ago at the International Super Computing conference in Germany, a quantum computer could end up being an accelerator for a traditional parallel supercomputer, which is used to do error correction and monitoring of qubits. Intel is also thinking this might happen.

The fussiness of superconducting qubits is probably one of the reasons why Intel is looking to spin qubits and a more standard semiconductor process to create a quantum computer chip whose state is easier to maintain. The other is that Intel is obviously an expert at manufacturing semiconductor devices. So, we think, the work with QuTech is as much about creating a testbed system and a software stack that might be portable as it is investing in this particular superconducting approach. Time will tell.

And time, indeed, it will take. Both Held and Clarke independently think it will take maybe eight to ten years to get a general purpose, universal quantum computer commercialized and operating at a useful scale.

It is research, so we are only coming to timing based on how we think we are going to solve a number of problems, says Held. There will be a milestone where a machine will be able to tackle interesting but small problems, and then there will be a full scale machine that is mature enough to be a general purpose, widely useful accelerator in the supercomputer environment or in the cloud. These will not be free-standing computers because they dont do a lot of things that a classical digital computer does really well. They could do them, because in theory any quantum computer can do anything a digital computer can do, but they dont do it well. It is going to take on the order of eight to ten years to solve these problems we are solving now. They are all engineering problems; the physicists have done an excellent job of finding feasible solutions out of the lab and scaling them out.

Clarke adds a note of caution, pointing out that there are a lot of physics problems that need to be solved for the packaging aspects of a quantum computer. But I think to solve the next level of physics problems, we need a healthy dose of engineering and process control, Clarke says. I think eight to ten years is probably fair. We are currently at mile one of a marathon. Intel is already in the lead pack. But when we think of a commercially relevant quantum computer, we think of one that is relevant to the general population, and moreover, one that would show up on Intels bottom line. They key is that we are building a system, and at first, that system is going to be pretty small but it is going to educate us about all aspects of the quantum computing stack. At the same time, we are designing that system for extensibility, both at the hardware level and at the architecture control level to get to many more qubits. We want to make the system better, and larger, and it is probably a bit premature to start assigning numbers to that other than to say that we are thinking about the longer term.

It seems we might need a quantum computer to figure out when we might get a quantum computer.

Categories: Cloud, Compute, HPC, Hyperscale

Tags: Delft, Intel, quantum, qubit, QuTech, spin qubit, Superconducting, TNO

See the rest here:
Intel Takes First Steps To Universal Quantum Computing

Qudits: The Real Future of Quantum Computing? – IEEE Spectrum

Instead of creating quantum computers based on qubits that can each adopt only two possible options, scientists have now developed a microchip that can generate qudits that can each assume 10 or more states, potentially opening up a new way to creating incredibly powerful quantum computers, a new study finds.

Classical computers switch transistors either on or off to symbolize data as ones and zeroes. In contrast, quantum computers use quantum bits, or qubitsthat, because of the bizarre nature of quantum physics, can be in a state ofsuperpositionwhere they simultaneously act as both 1 and 0.

The superpositions that qubits can adopt let them each help perform two calculations at once. If two qubitsare quantum-mechanically linked, orentangled,they can help perform four calculations simultaneously; three qubits, eight calculations; and so on. As a result, aquantum computer with 300 qubits could perform more calculations in an instant than there are atoms in the known universe, solving certain problems much faster than classical computers. However, superpositions are extraordinarily fragile, making it difficult to work with multiple qubits.

Most attempts at building practical quantum computers rely on particles that serve as qubits. However, scientists have long known that they could in principle use quditswith more than two states simultaneously. In principle, a quantum computer with two 32-state qudits, for example, would be able to perform as many operations as 10 qubits while skipping the challenges inherent with working with 10 qubits together.

Researchers used the setup pictured above to create, manipulate, and detect qudits. The experiment starts when a laser fires pulses of light into a micro-ring resonator, which in turn emits entangled pairs of photons.Because the ring has multiple resonances, the photons have optical spectrumswitha set of evenly spaced frequencies(red and blue peaks), a process known as spontaneous four-wave mixing (SFWM).The researchers were able to use each of thefrequencies to encode information, which means the photons act asqudits.Each quditis in a superposition of 10 possible states, extending the usual binary alphabet (0 and 1) of quantum bits.The researchers also showed they could perform basic gate operations on the qudits using optical filters and modulators, and then detect the results using single-photon counters.

Now scientists have for the first time created a microchip that can generate two entangled qudits each with 10 states, for 100 dimensions total, more than what six entangled qubits could generate. We have now achieved the compact and easy generation of high-dimensional quantum states, says study co-lead author Michael Kues, a quantum optics researcher at Canadas National Institute of Scientific Research, or INRS,its French acronym,in Varennes, Quebec.

The researchers developed a photonic chip fabricated using techniques similar to ones used for integrated circuits. A laser fires pulses of light into a micro-ring resonator, a 270-micrometer-diameter circle etched onto silica glass, which in turn emits entangled pairs of photons. Each photon is in a superposition of 10 possible wavelengths or colors.

For example, a high-dimensional photon can be red and yellow and green and blue, although the photons used here were in the infrared wavelength range, Kues says. Specifically, one photon from each pair spanned wavelengths from 1534 to 1550 nanometers, while the other spanned from 1550 to 1566 nanometers.

Using commercial off-the-shelf telecommunications components, the researchers showed they could manipulate these entangled photons. The basic capabilities they show are really what you need to do universal quantum computation, says quantum optics researcher Joseph Lukens at Oak Ridge National Laboratory, in Tennessee, who did not take part in this research. Its pretty exciting stuff.

In addition, by sending the entangled photons through a 24.2-kilometer-long optical fiber telecommunications system, the researchers showed that entanglement was preserved over large distances. This could prove useful for nigh-unhackable quantum communications applications, the researchers say.

What I think is amazing about our system is that it can be created using components that are out on the market, whereas other quantum computer technologies need state-of-the-art cryogenics, state-of-the-art superconductors, state-of-the-art magnets, saysstudy co-senior authorRoberto Morandotti, a physicistatINRSin Varennes. The fact that we use basic telecommunications components to access and control these states means that a lot of researchers could explore this area as well.

The scientists noted that current state-of-the-art components could conceivably generate entangled pairs of 96-state qudits, corresponding to more dimensions than 13 qubits. Conceptually, in principle, I dont see a limit to the number of states of qudits right now, Lukens, from Oak Ridge,says. I do think a 96-by-96-dimensional system is fairly reasonable, and achievable in the near future.

But he adds that several components of the experiment were not on the microchips, such as the programmable filters and phase modulators, which led to photon loss. Kues says that integrating such components with the rest of the chips and optimizing their micro-ring resonator would help reduce such losses to make their system more practical for use.

The next big challenge we will have to solve is to use our system for quantum computation and quantum communications applications, Kues says. While this will take some additional years, it is the final step required to achieve systems that can outperform classical computers and communications.

The scientists detailed their findings in the latest issue of the journal Nature.

Originally posted here:
Qudits: The Real Future of Quantum Computing? – IEEE Spectrum

quantum computing –

According to Intel, the building blocks of quantum computing, qubits, are very fragile. They can only operate at extremely low temperatures (250 times colder than deep space) and must be packaged carefully to prevent data loss. Intel’s research groups in Oregon and Arizona have found a way to manufacture 17-quibit chips with an architecture that makes them more reliable at higher temperatures and reduced RF interference between each qubit. The chip can send and receive 10 to 100 times more signal than comparable wire-bonded chips and has an advanced design that allows for the techniques to be applied to larger quantum integrated circuits, which are much bigger than typical silicon chips.

“Our quantum research has progressed to the point where our partner QuTech is simulating quantum algorithm workloads, and Intel is fabricating new qubit test chips on a regular basis in our leading-edge manufacturing facilities,” said Intel Labs’ Dr. Michael Mayberry. “Intel’s expertise in fabrication, control electronics and architecture sets us apart and will serve us well as we venture into new computing paradigms, from neuromorphic to quantum computing.”

Go here to read the rest:
quantum computing –

Quantum Computing | Intel Newsroom

Quantum computing is an exciting new computing paradigm with unique problems to be solved and new physics to be discovered. Quantum computing, in essence, is the ultimate in parallel computing, with the potential to tackle problems conventional computers cant handle. For example, quantum computers may simulate nature to advance research in chemistry, materials science and molecular modeling.

In 2015, Intel established a collaborative relationship with QuTech to accelerate advancements in quantum computing. The collaboration spans the entire quantum system or stack from qubit devices to the hardware and software architecture required to control these devices as well as quantum applications. All of these elements are essential to advancing quantum computing from research to reality.

Download A Quantum Computing Primer

Intels director of quantum hardware, Jim Clarke, holds the new 17-qubit superconducting test chip. (Credit: Intel Corporation)

Intels 17-qubit superconducting test chip for quantum computing has unique features for improved connectivity and better electrical and thermo-mechanical performance. (Credit: Intel Corporation)

Researchers work in the quantum computing lab at QuTech, Intels quantum research partner in the Netherlands. Intel in October 2017 provided QuTech a 17-qubit superconducting test chip for quantum computing. (Credit: QuTech)

Professor Leo DiCarlo poses in the quantum computing lab at QuTech, Intels quantum research partner in the Netherlands. Intel in October 2017 provided QuTech a 17-qubit superconducting test chip for quantum computing. (Credit: QuTech)

Intel is collaborating with QuTech in the Netherlands to advance quantum computing research. Intel in October 2017 provided QuTech a 17-qubit superconducting test chip for quantum computing. (Credit: Intel Corporation)

Intels new 17-qubit superconducting test chip packaged for delivery to research partners at QuTech, Intels quantum research partner in the Netherlands. Intel in October 2017 provided QuTech with the 17-qubit superconducting test chip for quantum computing. (Credit: Intel Corporation)

Read more here:
Quantum Computing | Intel Newsroom