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New collaborative research describes how electrons move through two different configurations of bilayer graphene, the atomically-thin form of carbon. These results provide insights that researchers could use to design more powerful and secure quantum computing platforms in the future.

Researchers describe how electrons move through two-dimensional layered graphene, findings that could lead to advances in the design of future quantum computing platforms.

New research published in Physical Review Letters describes how electrons move through two different configurations of bilayer graphene, the atomically-thin form of carbon. This study, the result of a collaboration between Brookhaven National Laboratory, the University of Pennsylvania, the University of New Hampshire, Stony Brook University, and Columbia University, provides insights that researchers could use to design more powerful and secure quantum computing platforms in the future.

Todays computer chips are based on our knowledge of how electrons move in semiconductors, specifically silicon, says first and co-corresponding author Zhongwei Dai, a postdoc at Brookhaven. But the physical properties of silicon are reaching a physical limit in terms of how small transistors can be made and how many can fit on a chip. If we can understand how electrons move at the small scale of a few nanometers in the reduced dimensions of 2-D materials, we may be able to unlock another way to utilize electrons for quantum information science.

When a material is designed at these small scales, to the size of a few nanometers, it confines the electrons to a space with dimensions that are the same as its own wavelength, causing the materials overall electronic and optical properties to change in a process called quantum confinement. In this study, the researchers used graphene to study these confinement effects in both electrons and photons, or particles of light.

The work relied upon two advances developed independently at Penn and Brookhaven. Researchers at Penn, including Zhaoli Gao, a former postdoc in the lab of Charlie Johnson who is now at The Chinese University of Hong Kong, used a unique gradient-alloy growth substrate to grow graphene with three different domain structures: single layer, Bernal stacked bilayer, and twisted bilayer. The graphene material was then transferred onto a special substrate developed at Brookhaven that allowed the researchers to probe both electronic and optical resonances of the system.

This is a very nice piece of collaborative work, says Johnson. It brings together exceptional capabilities from Brookhaven and Penn that allow us to make important measurements and discoveries that none of us could do on our own.

The researchers were able to detect both electronic and optical interlayer resonances and found that, in these resonant states, electrons move back and forth at the 2D interface at the same frequency. Their results also suggest that the distance between the two layers increases significantly in the twisted configuration, which influences how electrons move because of interlayer interactions. They also found that twisting one of the graphene layers by 30 also shifts the resonance to a lower energy.

Devices made out of rotated graphene may have very interesting and unexpected properties because of the increased interlayer spacing in which electrons can move, says co-corresponding author Jurek Sadowski from Brookhaven.

In the future, the researchers will fabricate new devices using twisted graphene while also building off the findings from this study to see how adding different materials to the layered graphene structure impacts downstream electronic and optical properties.

We look forward to continuing to work with our Brookhaven colleagues at the forefront of applications of two-dimensional materials in quantum science, Johnson says.

Reference: Quantum-Well Bound States in Graphene Heterostructure Interfaces by Zhongwei Dai, Zhaoli Gao, Sergey S. Pershoguba, Nikhil Tiwale, Ashwanth Subramanian, Qicheng Zhang, Calley Eads, Samuel A. Tenney, Richard M. Osgood, Chang-Yong Nam, Jiadong Zang, A.T. Charlie Johnson and Jerzy T. Sadowski, 20 August 2021, Physical Review Letters.DOI: 10.1103/PhysRevLett.127.086805

The complete list of co-authors includes Zhaoli Gao (now at The Chinese University of Hong Kong), Qicheng Zhang, and Charlie Johnson from Penn; Zhongwei Dai, Nikhil Tiwale, Calley Eads, Samuel A. Tenney, Chang-Yong Nam, and Jerzy T. Sadowski from Brookhaven; Sergey S. Pershogub, and Jiadong Zang from the University of New Hampshire; Ashwanth Subramanian from Stony Brook University; and Richard M. Osgood from Columbia University.

Charlie Johnson is the Rebecca W. Bushnell Professor of Physics and Astronomy in the Department of Physics and Astronomy in the School of Arts & Sciences at the University of Pennsylvania.

This research was supported by National Science Foundation grants MRSEC DMR- 1720530 and EAGER 1838412. Brookhaven National Laboratory is supported by the U.S. Department of Energys Office of Science.

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Atomically-Thin, Twisted Graphene Has Unique Properties That Could Advance Quantum Computing - SciTechDaily

Published on Tuesday, September 14, 2021

Several teams from the University of Chicago and Duality the worlds first accelerator focused exclusively on quantum technologies are pitching at the 2021 Chicago Venture Summit.

The venture capital conference takes place September 27-29 and brings together leading venture capital investors and innovation ecosystem leaders with founders.

>> Register for the Deep Tech Showcase, here.

Kicking off the conference on Monday, September 27, the Polsky Center for Entrepreneurship and Innovation and Argonnes Chain Reaction Innovations program are hosting the 2021 Deep Tech Showcase as part of the larger event. The virtual showcase is from 2:00 to 3:30 p.m. (CST).

UChicago and Duality teams pitching include:

// AddGraft Therapeutics is developing a CRISPR-based therapeutic technology using skin cells to treat addiction. The researchers have developed a therapeutic platform that, through a one-time and first-of-its-kind treatment, will effectively cure someone of alcohol use disorder (AUD). The treatment is long-lasting, highly effective, and minimally invasive.

This is completed by using skin epidermal progenitor cells to deliver one or more therapeutic agents. First, the researchers harvest skin stem cells from an AUD patient and genetically modify them using a precise molecular scissor CRISPR. This process will introduce genes that can produce molecules that will significantly reduce the motivation to take or seek alcohol. Then, they re-implant these skin cells into the original host through a skin graft. After the graft has been re-implanted, the skin graft is able to produce these molecules as a bio engine throughout the lifetime of the graft.

Team members:

// Arrow Immuneis developing next-generation biologics for immuno-oncology in solid tumors. The company is developing protein engineering technology to retain IO molecules in the tumor microenvironment, both to function as monotherapies and to enhance response to checkpoint inhibitor immunotherapy.

The company has developed a powerful approach to mask these compounds such that they are inactive in the periphery yet are activated within the tumor, to limit immune-related adverse events and open the therapeutic window.

Team members:

// Axion Technologies is a Tallahassee, FL-based company, developing a quantum random number generator for high-performance computing systems. Its design enables embedding of unique digital signatures for hardware authentication. The company has received a NSF SBIR award.

Team members:

// Esya Labs mission is the early, precise, and cost-effective detection of neurodegenerative diseases. Its first-in-class product for Alzheimers Diseasewill provide a 360-degree perspective enabling early diagnosis, a personalized treatment plan based on ranked drug effectiveness for any given patient, and monitoring disease progression.

The platform uses synthetic DNA strands that have been engineered to function in a specific way. These so-called DNA nanodevices are used to measure lysosomes performance by creating chemical maps of their activity a process that had previously not been possible. The company in

Team members:

// Nanopattern Technologies is commercializing a quantum dot ink that enables the manufacturing of the next generation of energy-efficient, bright, and fast refresh rate displays and recently received a $1 million NSF SBIR grant.

In addition to displays, NanoPatterns patented technology is capable of patterning oxide nanoparticles for optics applications and Near Infrared (NIR) quantum dots for multispectral sensor applications.

Team members:

// qBraid is developing a cloud-based platform for managed access to other quantum computing software and hardware. The platform includes qBraid Learn and qBraid Lab. qBraid Learn is ready to host any courses developed by the quantum computing ecosystem, but the team has also developed their own educational content. qBraid provides a streamlined experience for first-time learners through its QuBes (quantum beginners) course. Hosted on the qBraid-learn platform, QuBes brings students up to speed on all the background knowledge (mathematics, coding, and physics) necessary to then introduce quantum computing.

qBraid-Lab provides a cloud-based integrated development environment (IDE) for quantum software developers. Unlike other in-browser development platforms, qBraids ecosystem specifically optimizes for quantum computing by providing development environments with all common quantum computing packages pre-installed.

The platform is being used by more than 2500 users from top universities, financial institutions, and various national labs. qBraid has also announced recent collaborations with various government agencies (Quantum Algorithms Institute in British Columbia, the Chicago Quantum Exchange, and the QuSteam) in the US and Canada.

Team members:

// Quantopticon, based in the UK, develops software for simulating quantum-photonic devices. The software has applications chiefly in the budding fields of quantum computing and ultra-secure quantum communications.

Quantopticon specializes in modelling quantum systems of the solid-state type, which are commonly embedded in cavity structures in order to control and enhance specific optical transitions.Its software for modelling interactions of light with matter is underpinned by an original and proprietary general methodology developed by the team from first principles.

The purpose of their software is ultimately to save quantum-optical designers time and money, by eliminating the need to carry out repeated experiments to test and optimize physical prototypes.

Team members:

// Super.tech is developing software that accelerates quantum computing applications by optimizing across the system stack from algorithms to control pulses. The company in August announced the launch of a software platform endeavoring to make quantum computing commercially viable years sooner than otherwise possible.

The platform, calledSuperstaQ, connects applications to quantum computers from IBM Quantum, IonQ, and Rigetti, and optimizes software across the system stack to boost the performance of the underlying quantum computers.

Team members:

Of the teams presenting, Axion, qBraid, Quantopticon, and Super.tech were selected from a competitive pool of applicants from all over the globe and vetted by an internal review process to participate in Cohort 1 of Duality.

Launched in April 2021,Duality is the first-of-its-kind accelerator aimed at supporting next-generation startups focused on quantum science and technology. The 12-month program provides world-class business and entrepreneurship training from theUniversity of Chicago Booth School of Business, Polsky Center, and the opportunity to engage the networks, facilities, and programming from the Chicago Quantum Exchange, the University of Illinois Urbana-Champaign, Argonne National Laboratory, and P33.

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UChicago, Duality Teams to Pitch at 2021 Chicago Venture Summit - Polsky Center for Entrepreneurship and Innovation - Polsky Center for...