Argonne Qubit Platform Cuts Noise Thousands of Times Lower

A new qubit platform developed at the U.S. Department of Energy’s Argonne National Laboratory is demonstrating noise levels thousands of times lower than those plaguing most traditional qubits, a critical step toward stable and scalable quantum computing. The innovation relies on trapping single electrons on a surface of frozen neon gas, a fundamentally different approach from semiconductor or superconducting materials commonly used. This reduction in environmental disturbances allows the qubits to retain information longer, addressing a major challenge in building practical quantum computers capable of solving complex problems. “In previous work, we demonstrated the outstanding performance of our electron-on-neon qubit,” said Xu Han, an Argonne scientist and co-corresponding author. “By thoroughly characterizing the qubit’s noise properties, this latest study shows why its performance is so good.” The findings, a collaboration with the University of Notre Dame, are detailed in Nature Electronics.

Electron-on-Neon Qubit Platform Minimizes Environmental Noise

Unlike qubits built from semiconductors or superconductors, the neon platform inherently minimizes disturbances stemming from material defects and fabrication inconsistencies. The core innovation lies in the platform’s composition; solid neon, being chemically inert and remarkably free of impurities, presents a significantly quieter environment for delicate quantum states.

Experiments involved directing precisely timed microwave pulses through a resonator to manipulate the qubit and assess noise levels, even intentionally probing frequencies outside the qubit’s “sweet spot” to comprehensively evaluate environmental impacts. “There’s a particular frequency called the ‘sweet spot’ where the electron qubit becomes relatively insensitive to nearby electrical noise,” explained Dafei Jin, formerly of Argonne and now an associate professor at the University of Notre Dame. “However, in this work, we intentionally looked at frequencies outside this sweet spot. This enabled us to investigate how the solid-neon environment disturbs the qubit and to compare it with other materials.” The team’s findings reveal noise levels 10 to 10,000 times lower than those found in most semiconducting qubits, rivaling the best semiconductor results. Xu Han, an Argonne scientist, stated that “Our results prove that our technology is promising for quantum information processing at larger scales.” While some noise remains due to stray electrons and surface imperfections, ongoing research aims to further refine the platform and unlock its full potential for scalable quantum computing.

1 Millisecond Coherence Achieved with Novel Qubit Design

The pursuit of stable qubits remains a central challenge in realizing practical quantum computers; current devices struggle with maintaining quantum information due to environmental disturbances that introduce errors. While semiconductor and superconducting qubits dominate much of the research, a collaborative effort between Argonne National Laboratory and the University of Notre Dame has yielded a dramatically different approach, achieving a coherence time of 0.1 milliseconds, nearly a thousand times better than previous semiconducting qubit records. Researchers systematically probed the qubit’s environment with precisely timed microwave pulses, even examining frequencies outside the traditionally optimized “sweet spot” to fully characterize the disturbance.

Argonne CNM Characterization Reveals Low-Frequency Noise Performance

The collaborative effort also included researchers from the University of Chicago, Harvard University, Northeastern University, and Florida State University. A key finding detailed in the recent study is the platform’s remarkably low noise levels, measured as thousands of times lower than those found in traditional qubits. This improvement stems from the unique properties of solid neon, which is chemically inert and largely free of the impurities that plague other qubit materials. The team discovered that noise levels in the neon qubit platform are comparable to the lowest semiconductor records, and significantly lower than most semiconducting qubits, a feat achieved despite identifying some residual noise from stray electrons and surface imperfections. “We have begun follow-up work to mitigate this noise and further optimize the qubit,” Jin stated.

Solid Neon Fabrication Simplifies Qubit Production & Cost

The pursuit of stable, scalable qubits received a significant boost from research demonstrating a platform built on an unexpectedly simple foundation: frozen neon. Beyond the immediate gains in qubit coherence, the fabrication process itself offers a pathway to dramatically lower production costs compared to prevailing semiconductor and superconducting approaches. This reduction in environmental disturbances isn’t simply a matter of material purity; solid neon’s inherent chemical inertness and lack of impurities contribute to a remarkably stable quantum environment. The simplicity extends to fabrication, as the neon qubits utilize electrons sourced from standard light bulb filaments, significantly reducing material expenses.