Cornell Physicists Quantify Quantum Information Preservation Duration

Cornell physicists have provided the first quantitative determination of how long dynamical freezing can preserve quantum information. This research indicates that quantum systems can maintain a stable, "frozen" state for an extended duration, potentially approaching the age of the universe, offering a strategy for addressing information loss in quantum computing. The findings were published in Physical Review X on February 27.

"Quantum systems can maintain a stable, 'frozen' state for an extended duration, potentially approaching the age of the universe."

The Challenge of Quantum Information Preservation

Preserving quantum information is a fundamental challenge for developing functional quantum computing systems. Interacting quantum systems are typically chaotic and adhere to thermodynamic laws, which leads to information loss over time. Dynamical freezing has been identified as an exception to these laws, where quantum systems, when stimulated at specific frequencies, can circumvent information loss processes. However, the precise duration for which this phenomenon could stabilize quantum information remained unquantified.

Quantifying Extended Preservation

A team of physicists from Cornell University has now quantified the duration of dynamical freezing. Utilizing a new mathematical framework and analytical calculations, their research demonstrates that the frozen state can be stabilized for an extended period, which could potentially approach the age of the universe. While robust for significantly extended timescales, the frozen state is not permanent and will eventually thermalize through extremely rare quantum processes.

Debanjan Chowdhury, an associate professor of physics at Cornell, and co-first authors Haoyu Guo and Rohit Mukherjee contributed to the study.

The frozen state can be stabilized for a period "potentially approaching the age of the universe."

The Mechanism of Dynamical Freezing

The stability of the frozen state relies on a persistent periodic drive. Rohit Mukherjee explained that this continuous drive is necessary to maintain the frozen state, similar to how regular pushes maintain the motion of a playground swing. Debanjan Chowdhury further noted that the periodic drive, applied at precisely tuned frequencies, facilitates a quantum mechanical cancellation of processes that typically lead to chaos. Haoyu Guo described the eventual thermalization as sudden quantum jumps to different states, a phenomenon permitted by quantum physics where particles transition without crossing intervening energy barriers.

"The periodic drive, applied at precisely tuned frequencies, facilitates a quantum mechanical cancellation of processes that typically lead to chaos."

Implications for Quantum Computing

This theoretical work carries significant experimental implications for various quantum computing platforms. As quantum processors increase in size and qubit counts, maintaining coherence becomes more challenging, as even minor chaotic processes can trigger errors across numerous components. Dynamical freezing is considered a promising strategy for managing these chaotic processes and for scaling quantum systems from a few qubits to potentially millions in future devices. The research indicates that dynamical freezing represents a finely balanced state whose lifetime can now be predicted from fundamental principles.

Publication and Funding

The findings were published in Physical Review X on February 27 in a paper titled "Floquet Thermalization via Instantons Near Dynamical Freezing." The research received support from the Alfred P. Sloan Foundation, the National Science Foundation, and a New Frontier Grant from the College of Arts and Sciences.