Amplifying quantum correlations with quench dynamics in a quantum spin chain: Steady-states versus ground-states

Abstract

We analyze the behavior of steady-state quantum correlations (QCs) in the spin-1/2 transverse field XY chains analytically, in terms of quench dynamics at zerotemperature. We show that steady-state QCs are strikingly greater than the equilibrium ones in its ground-state, where a single quench is performed from ferrointo paramagnetic phases. Another framework to amplify the QCs here is a feasible protocol called double quench dynamics. To fulfill this purpose, we probe a middle quench point and spending time T (defined as the time passing from the middle quench point before reaching a second quench). By doing so, both single and double quenches act as practical tools to control the enhancement of the steady-state QCs in the final quenched point. In particular, and in parallel to expectations for some other quantities, we indicate that the nonequilibrium quantum phase transitions also can be identified by nonanalyticities in the steady-state QCs. Our work may be testable with the current class of trappedion or ultracold-atom experiments, and encourage the possible potential in the quantum information field.

Late-time critical behavior of local string-like observables under quantum quenches

“…Even so, it is usually difficult to understand how equilibrium critical phenomena can manifest in generic high energy excited states of a system. In this light, there has been an extensive search for footprints of quantum criticality in excited and particularly out of * souvik@iitk.ac.in equilibrium systems [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Particularly, Ref.…”