A revolutionary new Qubit platform can transform quantum computing

The digital device you use to view this article no doubt uses a bit, which can be 0 or 1, as the basic unit of information. However, scientists around the world are vying to develop a new type of computer based on the use of quantum bits or qubits, which can be both 0 and 1 and one day could solve complex problems beyond all classical supercomputers.

A research team led by scientists from the US Department of Energy’s Argon National Laboratory (DOE), in close collaboration with FAMU-FSU Associate Professor of Mechanical Engineering Wei Guo College of Engineering, announced the creation of a new qubit platform that shows great promise to be developed in future quantum computers. Their work was published in the journal nature.

“Quantum computers can be a revolutionary computing tool that is virtually impossible for traditional computers, but there is still work to be done to make them a reality,” said Guo, co-author of the book. “With this study, we believe we have a breakthrough that is a long way to go to create qubits that help realize the potential of this technology.”

The team created its qubit by freezing neon gas in a solid at very low temperatures, spraying electrons from a light bulb on the solid and capturing a single electron there.

FAMU-FSU College of Engineering Associate Professor of Mechanical Engineering Wei Guo. Credit: Florida State University

Although there are many options for choosing qubit types, the team chose the simplest – a single electron. Heating a simple light bulb, such as you can find in a toy, can easily launch an endless supply of electrons.

One important quality for qubits is their ability to remain in a 0 or 1 state for a long time, known as “coherence time”. This time is limited and the limitation is determined by the way the qubits interact with their environment. Defects in the qubit system can significantly reduce coherence time.

For this reason, the team chose to capture an electron on a super-pure neon surface in a vacuum. Neon is one of only six inert elements, which means that it does not react with other elements.

“Because of this inertia, solid neon can serve as the cleanest possible solid in a vacuum to receive and protect all qubits from disturbance,” said Dafei Jin, an Argon scientist and lead researcher on the project.

By using a chip-scale superconducting resonator – such as a miniature microwave oven – the team was able to manipulate the captured electrons, allowing them to read and store qubit information, making it useful for use in future quantum computers.

Previous research has used liquid helium as an electron retention medium. This material was easy to make without defects, but vibrations on the surface without liquid can easily disrupt the state of the electrons and therefore compromise the work of the qubit.

Solid neon offers a material with few defects that does not vibrate like liquid helium. After building its platform, the team performed real-time qubit operations using microwave photons on a captured electron and characterizing its quantum properties. These tests have shown that solid neon provides a healthy environment for an electron with very low electrical noise to disturb it. Most importantly, the qubit achieved times of coherence in the quantum state, competing with other most modern qubits.

The simplicity of the qubit platform must also lend itself to simple, inexpensive production, Gene said.

The promise of[{” attribute=””>quantum computing lies in the ability of this next-generation technology to calculate certain problems much faster than classical computers. Researchers aim to combine long coherence times with the ability of multiple qubits to link together — known as entanglement. Quantum computers thereby could find the answers to problems that would take a classical computer many years to resolve.

Consider a problem where researchers want to find the lowest energy configuration of a protein made of many amino acids. These amino acids can fold in trillions of ways that no classical computer has the memory to handle. With quantum computing, one can use entangled qubits to create a superposition of all folding configurations — providing the ability to check all possible answers at the same time and solve the problem more efficiently.

“Researchers would just need to do one calculation, instead of trying trillions of possible configurations,” Guo said.

For more on this research, see New Qubit Breakthrough Could Revolutionize Quantum Computing.

Reference: “Single electrons on solid neon as a solid-state qubit platform” by Xianjing Zhou, Gerwin Koolstra, Xufeng Zhang, Ge Yang, Xu Han, Brennan Dizdar, Xinhao Li, Ralu Divan, Wei Guo, Kater W. Murch, David I. Schuster and Dafei Jin, 4 May 2022, Nature.
DOI: 10.1038/s41586-022-04539-x

The team published its findings in a Nature article titled “Single electrons on solid neon as a solid-state qubit platform.” In addition to Jin, Argonne contributors include first author Xianjing Zhou, Xufeng Zhang, Xu Han, Xinhao Li, and Ralu Divan. Contributors from the University of Chicago were David Schuster and Brennan Dizdar. Other co-authors were Kater Murch of Washington University in St. Louis, Gerwin Koolstra of Lawrence Berkeley National Laboratory, and Ge Yang of Massachusetts Institute of Technology.

Funding for the Argonne research primarily came from the DOE Office of Basic Energy Sciences, Argonne’s Laboratory Directed Research and Development program and the Julian Schwinger Foundation for Physics Research. Guo is supported by the National Science Foundation and the National High Magnetic Field Laboratory.