A major milestone has been reached in a new quantum computing architecture

Newswise — Consistency is the cornerstone of effective communication, whether in writing, speaking or processing information. This principle applies to the quantum bits, or qubits, that make up blocks Quantum computing. Quantum computing could one day tackle previously insurmountable challenges in climate prediction, material design, drug discovery, and more.

A team led by the US Department of Energy's (DOE) Argonne National Laboratory has reached an important milestone toward the future. Quantum computing. They extended the sequencing time for their new type of qubit to an impressive 0.1 milliseconds—almost a thousand times better than the previous record.

Instead of 10 to 100 operations during the coherence of conventional qubits of electronic charge, our qubits can perform 10,000 with very high accuracy and speed. – Dufei Jin, professor at the University of Notre Dame, with a joint appointment at the Argonne Center for Nanoscale Materials.

In everyday life, 0.1 millisecond is as fleeting as the blink of an eye. However, in the quantum world, it represents a long enough window for a qubit to perform many thousands of operations.

Unlike classical bits, qubits can apparently exist in both states, 0 and 1. For any working qubit, maintaining this mixed state for a sufficiently long consistent time is essential. The challenge is to protect the qubit from the constant wave of disruptive noise surrounding it.

Team qubits are coded quantum Information in electron motion (charge) states. Because of this, they are called charge qubits.

“Among the various existing qubits, electronic charge qubits are particularly attractive due to their ease of fabrication and operation, as well as their compatibility with existing classical computer infrastructure,” said Dafei Jin, a professor at the University of Notre Dame. Argon and the principal investigator of the project. ​”This simplicity should translate into a low-cost way to build and run large-scale quantum computers.”

Gene is a former scientist at the Center for Nanoscale Materials (CNM), a DOE Office of Science user facility at Argonne. While there, he led the discovery of their new type of qubit, reported last year.

A team qubit is a single electron placed on the surface of ultrapure, solid neon in a vacuum. Neon is important because it resists environmental degradation. Neon is one of those elements that does not react with other elements. The neon platform retains the electron qubit and essentially provides long coherence times.

“Due to the small footprint of single electrons on solid neon, qubits made with them are more compact and promising for scaling up to multiple connected qubits,” said Xu Han, a CNM assistant scientist at the Pritzker School of Molecular Biology. Engineering at the University of Chicago. ​”These attributes, along with the coherence time, make our electronic qubit particularly attractive.”

After continuous experimental optimization, the team not only improved the quality of the neon surface, but also significantly reduced the disruptive signals. As reported in Nature Physics, their work resulted in a coherence time of 0.1 millisecond. This is about a thousandfold increase from the initial 0.1 microseconds.

“The long lifetime of our electronic qubit allows us to monitor and interrogate single qubit states with very high fidelity,” said Xinhao Li, an Argonne postdoctoral fellow and co-first author of the paper. This time far exceeds the requirements Quantum computing.

“Instead of 10 to 100 operations in the sequential time of conventional qubits of electronic charge, our qubits can perform 10,000 with very high precision and speed,” Jin said.

Another important attribute of a qubit is its scalability to connect to many other qubits. The team achieved a major milestone by showing that two electron qubits can be attached to the same superconducting circuit so that information can be transferred between them through the circuit. This marks a crucial step towards two-qubit entanglement, which is a critical aspect Quantum computing.

The team does not yet have a fully optimized electron qubit and will continue to work on further extending the sequence time, as well as entangling two or more qubits.

The work was funded by the DOE Office of Basic Energy Sciences; Laboratory Research and Development Award from Argonne; and Q-NEXT, the DOE Energy National Quantum Information Science Research Center, headquartered in Argonne. Additional funding came from the Julian Schwinger Physics Research Foundation and the National Science Foundation.

This study was published in Physics of nature. In addition to Jin, Han, and Li, Argon's authors include postdocs Xianjing Zhou and Qianfan Chen. Other authors include co-corresponding author David Schuster, a former physics professor at the University of Chicago now at Stanford University, and Xufeng Zhang, a former CNM fellow and now a professor at Northeastern University. Also contributing are Gerwin Kulstra, Ge Yang, Brennan Dizdar, Yizhong Huang, and Christopher S. Wang.

Collaborating institutions include Lawrence Berkeley National Laboratory, Massachusetts Institute of Technology, Northeastern University, Stanford University, University of Chicago, and University of Notre Dame.

About Argon Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the DOE Nanoscale Science Research Centers, the premier national user facilities for nanoscale interdisciplinary research supported by the DOE Office of Science. Together, the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities in the fabrication, processing, characterization and modeling of nanoscale materials and represent the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia, and Los Alamos National Laboratories. For more information on DOE NSRCs, please visit https://sci​ence.osti sér-FacIlItIe-at-a-Glance.

Argonne National Laboratory Seeks solutions to pressing national problems in science and technology. As the nation's first national laboratory, Argonne conducts advanced basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state, and municipal agencies to help them solve specific problems, advance America's scientific leadership, and prepare the nation for a better future. With employees from more than 60 countries, Argonne is run UChicago Argonne, LLC for US Department of Energy Office of Science.

US Department of Energy Office of Science is the largest supporter of basic research in the physical sciences in the United States and works to address some of the most pressing challenges of our time. For more information visit https://energy.gov/science.