Tailoring Dynamical Quantum Phase Transitions via Double-Mode Squeezing Manipulation

TL;DR

This paper introduces a method to control dynamical quantum phase transitions in the XY chain by applying double-mode squeezing to the initial state, revealing universal behaviors and entanglement dynamics.

Contribution

It demonstrates how initial-state squeezing can be used to tailor and induce universal dynamical quantum phase transitions in the XY model, depending on symmetry considerations.

Findings

Squeezing breaks or preserves particle-hole symmetry, affecting DQPTs.

Universal DQPTs occur at a specific squeezing strength, independent of quench path.

Maximal entanglement modes coincide with critical momenta and lead to geometric phase jumps.

Abstract

We propose a protocol to tailor dynamical quantum phase transitions (DQPTs) by double-mode squeezing onto the initial state in the XY chain. The effect of squeezing depends critically on the system's symmetry and parameters. When the squeezing operator breaks particle-hole symmetry (PHS), DQPTs become highly tunable, allowing one to either induce transitions within a single phase or suppress them. Remarkably, when PHS is preserved and the squeezing strength reaches $r=\pi/4$, a universal class of DQPTs emerges, independent of the quench path. This universality is characterized by two key features: (i) the collapse of all Fisher zeros onto the real-time axis, and (ii) the saturation of intermode entanglement to its maximum in each $(k,-k)$ modes. Moreover, the critical momenta governing the DQPTs coincide exactly with the modes attaining the maximal entanglement. At this universal point, the dynamical phase vanishes, leading to a purely geometric evolution marked by $\pi$-jumps in the Pancharatnam geometric phase. Our work establishes initial-state squeezing as a versatile tool for tailoring far-from-equilibrium criticality and reveals a direct link between entanglement saturation and universal nonanalytic dynamics.