Dual Role of Squeezed-Reservoir in Quantum Phase Synchronization: Boosting and Blockade

TL;DR

This paper investigates how a squeezed reservoir can both enhance and suppress quantum phase synchronization in a driven two-level system, revealing mechanisms for control and blockade.

Contribution

It demonstrates the dual role of squeezed reservoirs in inducing stable oscillations and actively suppressing synchronization through angle tuning.

Findings

Squeezed reservoir induces a stable limit cycle, transforming the TLS into a self-sustained oscillator.

Enhanced synchronization characterized by increased phase locking and narrower Arnold tongue.

Squeezing angle controls synchronization, enabling blockade via quenching of coherence.

Abstract

This study explores the dual role of a squeezed reservoir in controlling the quantum phase synchronization of a driven two-level system. We first demonstrate, through a Liouvillian eigen-spectrum analysis, that the squeezed reservoir can induce a stable limit cycle, transforming the passive TLS into a genuine self-sustained oscillator. This enables a qualitative transition from a weak ``forced response" to a robust, high-quality synchronization (or entrainment). This enhancement is characterized not only by a greater degree of phase locking but also by an increased frequency selectivity, manifested as a narrower Arnold tongue. More strikingly, we reveal that the squeezing angle acts as a control parameter to actively suppress synchronization. By tuning this angle, the reservoir can drive the system into a classical mixed state, inducing a quantum synchronization blockade via the quenching of steady-state coherence. Our findings establish squeezed-reservoir engineering as a versatile strategy for actively modulating quantum synchronization, with feasible implementations in circuit quantum electrodynamics.