Computing power is reaching a crisis point. If we continue to follow a trend in place since computers were introduced, by 2040 we will not have the capability to power all of the machines in the world. Unless we can crack quantum computing.
Quantum computers promise faster speeds and stronger security than their classical counterpart and scientists have been striving to create a quantum computer for decades. But what is quantum computing and why have we not achieved it yet?
Quantum computing differs to classical computing in one fundamental way the way information is stored. Quantum computing makes the most of a strange property of quantum mechanics, called superposition. It means one unit can hold much more information than the equivalent in classical computing.
In computing, information is stored in bits in either the state 1 or 0, like a light switch either turned on or off. By contrast, in quantum computing the unit of information can be 1 or 0, or a superposition of the two states.
Think of it like a sphere, with a 1 written at the north pole and a 0 at the south. A classical bit can be found at either pole, but a quantum bit, or qubit, could be found on any point on the surface of the sphere.
Quantum bits that can be on and off at the same time, provide a revolutionary high-performance paradigm where information is stored and processed more efficiently," Dr Kuei-Lin Chiu, who researches quantum mechanical behaviour of materials at the Massachusetts Institute of Technology, told Alphr.
The ability to store a much greater amount of information in one unit means quantum computing has the potential to be faster and more energy efficient than computers we use today. So why is it so hard to achieve?
Qubits, the backbone of a quantum computer, are tricky to make and, once made, are even harder to control; scientists must get them to interact in specific ways that would work in a quantum computer.
Researchers have tried using superconducting materials, ions held in ion traps or individual neutral atoms, as well as molecules of varying complexity to build them. But, making them hold onto quantum information for a long time is proving difficult.
In recent research, scientists at MIT devised a new approach, using a cluster of simple molecules made of just two atoms as qubits.
We are using ultracold molecules as qubits Professor Martin Zwierlein, lead author of the paper told Alphr. Molecules have long been proposed as a carrier of quantum information, with very advantageous properties over other systems like atoms, ions, superconducting qubits etc.
Here we show for the first time that you can store such quantum information for extended periods of time in a gas of ultracold molecules. Of course, an eventual quantum computer will have to also make calculations, i.e. have the qubits interact with each other to realise so-called gates. But first, you need to show that you can even hold on to quantum information, and thats what we have done.
The qubits created were found to be capable of holding onto the quantum information for longer than previous attempts, but still only for one second. This might sound short, but it is "in fact on the order of a thousand times longer than a comparable experiment that has been done" explained Zwierlein.
It is not just qubits, however. Scientists also need to work out what to make the quantum computing chips out of.
Chius paper, published earlier this year, found ultra-thin layers of materials could form the basis for a quantum computing chip. The interesting thing about this research is how we choose the right material, find out its unique properties and use its advantage to build a suitable qubit, Chiu, told Alphr.
Moores Law predicts that the density of transistors on silicon chips doubleapproximately every 18 months, Chiu told Alphr. However, these progressively shrunken transistors will eventually reach a small scale where quantum mechanics play an important role.
Moores Law, which Chiu referred to, is a computing term developed by Intel co-founder Gordon Moore in 1970. It states that the overall processing power for computers doubles about every two years. As Chiu states, the density of the chips decreases a problem that quantum computing chips can potentially answer.
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What is quantum computing and why does the future of Earth depend on it? - Alphr