Detecting quantumness with generalized Loschmidt echoes

Abstract

Loschmidt echoes are a well-established method to characterize dynamical properties such as quantum chaos and sensitivity to perturbations. Here we present a straightforward generalization that identifies non-classical dynamical behavior. The generalized echoes involve four forward-backward time propagators. If these propagators do not commute, one can readily identify signatures of this property in the relations between echoes. As an example, detection of intrinsic non-commuting quantum features is analyzed in critical dynamics of a spin chain. Interestingly, this phenomenon is also observed for Gaussian dynamics and high temperature limits which are generally regarded as classical.

10 pages, 2 figures

References in corpus (15)

• Quantum sensing
• Dynamics of quantum phase transition: exact solution in quantum Ising model
• Decay of Loschmidt Echo Enhanced by Quantum Criticality
• Dynamics of Loschmidt echoes and fidelity decay
• Leggett-Garg Inequalities
• Golden rule decay versus Lyapunov decay of the quantum Loschmidt echo
• Decoherence and the Loschmidt echo
• Information Scrambling and Loschmidt Echo
• Incompatible measurements in quantum information science
• Emergent perturbation independent decay of the Loschmidt echo in a many-spin system studied through scaled dipolar dynamics
• Short time decay of the Loschmidt echo
• Decoherence induced by a dynamic spin environment (I): The universal regime
• Irreversibility, Loschmidt echo, and thermodynamic uncertainty relation
• Semiclassical Theory of Time-Reversal Focusing
• Violation of Diagonal Non-Invasiveness: A Hallmark of Non-Classical Memory Effects