Qubit’s new revolutionary 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 in a hurry to develop a a new kind of computer based on the use of quantum bits or qubits that can be 0 and 1 at the same time and one day can solve complex problems outside of any classic supercomputer.

Research team led by scientists from the US Department of Energy (DOE) Argon National Laboratory, in close collaboration with FAMU-FSU College of Engineering, Associate Professor of Mechanical Engineering Wei Guo, announced the creation of a new qubit platform that shows great development prospects in future quantum computers. Their work is published in a journal Nature.

“Quantum computers could be a revolutionary tool for computing, which is virtually impossible for classic computers, but there is still work to be done to make them a reality,” said Guo, co-author. “Through this study, we believe we have a breakthrough that leads a long way to creating qubits that help realize the potential of this technology.”

The team created its qubit by freezing neon gas into a solid at very low temperatures, spraying electrons from a light bulb onto a solid and capturing one electron there.

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

Although there are many variants of qubit types, the team chose the simplest – one electron. Heating a simple light thread that you can find in a baby toy can easily release an endless supply of electrons.

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

For this reason, the team decided to hold the electron on a superficial solid neon surface in a vacuum. Neon is one of the six inert elements, which means that it does not react with other elements.

“Because of this inertia, solid neon can serve as the purest solid in a vacuum to accommodate and protect any qubits from disturbance,” said Dafei Jin, an Argon scientist and principal investigator of the project.

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

Previous studies have used liquid helium as a medium to hold electrons. This material was easy to make without defects, but the vibration-free surface of the liquid could easily disrupt the state of the electrons and thus jeopardize the performance of the qubit.

Solid neon offers a material with several defects that does not vibrate like liquid helium. After building its platform, the team conducted qubit operations in real time using microwave photons on the captured electron and characterized its quantum properties. These tests demonstrated that solid neon provides a reliable environment for an electron with very low electrical noise to excite it. Most importantly, the qubit has reached a time of coherence in the quantum state, competitive with other modern qubits.

The simplicity of the qubit platform should also lend itself to simple and cheap production, Gene said.

The promise of Fr.[{” 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.