Stark localization as a resource for weak-field sensing with super-Heisenberg precision

TL;DR

This paper demonstrates that Stark localization can be exploited for highly precise weak-field gradient sensing, achieving super-Heisenberg sensitivity in the extended phase and analyzing the effects of thermal fluctuations and interactions.

Contribution

It introduces a novel use of Stark localized systems as quantum sensors with super-Heisenberg precision, including critical exponents and robustness analysis.

Findings

Super-Heisenberg precision in the extended phase

Universal convergence to the thermodynamic limit in the localized phase

Thermal fluctuations reduce but do not eliminate quantum advantage

Abstract

Gradient fields can effectively suppress particle tunneling in a lattice and localize the wave function at all energy scales, a phenomenon known as Stark localization. Here, we show that Stark systems can be used as a probe for the precise measurement of gradient fields, particularly in the weak-field regime where most sensors do not operate optimally. In the extended phase, Stark probes achieve super-Heisenberg precision, which is well beyond most of the known quantum sensing schemes. In the localized phase, the precision drops in a universal way showing fast convergence to the thermodynamic limit. For single-particle probes, we show that quantum-enhanced sensitivity, with super-Heisenberg precision, can be achieved through a simple position measurement for all the eigenstates across the entire spectrum. For such probes, we have identified several critical exponents of the Stark localization transition and established their relationship. Thermal fluctuations, whose universal behavior is identified, reduce the precision from super-Heisenberg to Heisenberg, still outperforming classical sensors. Multiparticle interacting probes also achieve super-Heisenberg scaling in their extended phase, which shows even further enhancement near the transition point. Quantum-enhanced sensitivity is still achievable even when state preparation time is included in resource analysis.