Quantum Parameter Estimation for Detectors in Constantly Accelerated Motion

Abstract: We investigate quantum parameter estimation by analyzing the dynamics of quantum Fisher information (QFI) for the state parameters of accelerated detectors undergoing four different acceleration scenarios: linear, cusped, catenary, and circular motions. Our results show that QFI for the acceleration parameter converges to a nonnegative asymptotic value over long evolution times, with this value strongly dependent on the specific acceleration scenario. In contrast, QFI for the weight parameter degrades to zero over time. Notably, for sufficiently large accelerations, optimal precision in estimating the acceleration parameter can be achieved within a finite evolution time rather than requiring an infinitely long measurement duration. Comparing different scenarios, we find that for small accelerations relative to the detector's energy gap, linear motion provides the most accurate estimation of the weight parameter, introducing the least noise among all scenarios. However, for large accelerations, circular motion becomes the optimal scenario for estimating the weight parameter. This behavior stands in sharp contrast to the estimation of the acceleration parameter, where circular motion is optimal both for small accelerations and for large accelerations over extremely long evolution times. These distinctions in QFI may provide a new tool for identifying the specific acceleration scenario of an accelerated detector.