Anomalously extended Floquet prethermal lifetimes and applications to long-time quantum sensing

TL;DR

This paper introduces a new quantum control technique that significantly extends Floquet prethermal lifetimes in quantum systems, enabling long-duration quantum sensing and advancing the stability of driven quantum states.

Contribution

A novel off-resonance, short-angle excitation method that dramatically prolongs Floquet prethermal lifetimes in quantum many-body systems, demonstrated on diamond nuclear spins.

Findings

Achieved a prethermal lifetime of ~800 seconds at 100 K.

Extended spin lifetime by over 533,000 times without prethermalization.

Enabled continuous quantum sensing for approximately 10 minutes at room temperature.

Abstract

Floquet prethermalization is observed in periodically driven quantum many-body systems where the system avoids heating and maintains a stable, non-equilibrium state, for extended periods. Here we introduce a novel quantum control method using off-resonance and short-angle excitation to significantly extend Floquet prethermal lifetimes. This is demonstrated on randomly positioned, dipolar-coupled, 13C nuclear spins in diamond, but the methodology is broadly applicable. We achieve a lifetime $T_2'~800 s at 100 K while tracking the transition to the prethermal state quasi-continuously. This corresponds to a >533,000-fold extension over the bare spin lifetime without prethermalization, and constitutes a new record both in terms of absolute lifetime as well as the total number of Floquet pulses applied (here exceeding 7 million). Using Laplace inversion, we develop a new form of noise spectroscopy that provides insights into the origin of the lifetime extension. Finally, we demonstrate applications of these extended lifetimes in long-time, reinitialization-free quantum sensing of time-varying magnetic fields continuously for ~10 minutes at room temperature. Our work facilitates new opportunities for stabilizing driven quantum systems through Floquet control, and opens novel applications for continuously interrogated, long-time responsive quantum sensors.