Critical sensing with a single bosonic mode without boson-boson interactions

TL;DR

This paper proposes a simple quantum sensing scheme using a single parametrically-driven bosonic mode with many non-interacting bosons, achieving criticality-enhanced sensitivity without requiring thermodynamic limits or fine control.

Contribution

It introduces a novel critical quantum sensing method that operates with a single bosonic mode, avoiding complex interactions and scaling requirements of previous systems.

Findings

Quantum Fisher information is enhanced at the critical point.

Numerical simulations confirm diverging variance at criticality.

The scheme is feasible with current parametric driving techniques.

Abstract

Critical phenomena of quantum systems are useful for enhancement of quantum sensing. However, experimental realizations of criticality enhancement have been confined to very few systems, owing to the stringent requirements, including the thermodynamical or scaling limit, and fine control of interacting quantum susystems or particles. We here propose a simple critical quantum sensing scheme that requires neither of these conditions. The critical system is realized with a single parametrically-driven bosonic mode involving many non-interacting bosons. We calculate the quantum Fisher information, and perform a simulation, which confirms the criticality-enabled enhancement. We further detail the response of one of the quadratures to the variation of the control parameter. The numerical results reveal that its inverted variance exhibits a diverging behavior at the critical point. Based on the presently available control techniques of parametric driving, we expect our scheme can be realized in different systems, e.g., ion traps and superconducting circuits.