Dynamics of quantum Fisher and Wigner-Yanase skew information following a noisy quench

TL;DR

This paper investigates how noise affects the evolution of quantum coherence measures, specifically quantum Fisher information and Wigner-Yanase skew information, in a quenched transverse-field Ising model near a quantum critical point, revealing exponential decay and linear scaling with noise.

Contribution

It introduces an analysis of quantum coherence dynamics under noisy quenches, highlighting the exponential decay and linear scaling behaviors, which are novel insights compared to noiseless cases.

Findings

QFI and WYSI increase monotonically in noiseless quenches.

Noise causes exponential decay of coherence measures.

Maximum coherence scales linearly with noise variance.

Abstract

We study the effect of noise on the dynamics of the transverse-field Ising model quenched across a quantum critical point. To quantify two-spin correlations, we employ the quantum Fisher information (QFI) and the Wigner-Yanase skew information (WYSI) as measures of quantum coherence. In the noiseless case, in contrast to the dynamics of entanglement in anisotropic XY chains, both QFI and WYSI increase monotonically with the ramp quench time, approaching their adiabatic limits without exhibiting any Kibble-Zurek type scaling with quench duration. In contrast, when noise is added to the quench protocol, the coherence dynamics change qualitatively: QFI and WYSI both decay exponentially with the time scale of a ramp quench, with an exponent determined by the noise intensity. Furthermore, the maximum ramp time, at which either of these measures reach their maximum, scales linearly with the noise variance, featuring the same exponent that determines the optimal annealing time for minimizing defect production in noisy quantum annealing.