Finite-size scaling of coherence and steered coherence in the Lipkin-Meshkov-Glick model

Abstract

Quantum coherence reflects the origin of quantumness and might be capable of extracting the subtle nature of a system. We investigate the ground-state coherence and steered coherence in the Lipkin-Meshkov-Glick model and show that they detect faithfully the quantum phase transitions of this model. Moreover, we carry out scaling analysis on the coherence and steered coherence by using the continuous unitary transformation method, and it is found that they show different scaling behaviors in different phase regions of this model. These results may provide useful insights into the mechanism underlying quantum criticality in many-body systems.

Quantum quench thermodynamics at high temperatures

“…This started with entanglement measures [7,8] (or some derivatives of it), which can show nonanalytic behavior at a quantum critical point. Similar analysis was later extended to mutual information, classical correlations and quantum discord [9,10], and more recently to quantifiers of coherence [11][12][13][14][15][16][17] in several spin models. Commonly, the singularities in these quantities disappear at finite T , and attempts to estimate the critical point from some extrema of these functions generally becomes poorer with increasing temperature.…”