Observable geometric phase induced by a cyclically evolving dissipative process

Dissipative generation of pure steady states and a gambler's ruin problem

We consider an open quantum system, with dissipation applied only to a part of its degrees of freedom, evolving via a quantum Markov dynamics. We demonstrate that, in the Zeno regime of large dissipation, the relaxation of the quantum system towards a pure quantum state is linked to the evolution of a classical Markov process towards a single absorbing state. The rates of the associated classical Markov process are determined by the original quantum dynamics. Extension of this correspondence to absorbing states with internal structure allows us to establish a general criterion for having a Zen…

Geometric phase accumulated in a driven quantum system coupled to an structured environment

We study the role of driving in a two-level system evolving under the presence of a structured environment. We find that adding a periodical modulation to the two-level system can greatly enhance the survival of the geometric phase for many time periods. We show that this effect is mainly important for a markovian regimen but can still be found when the environment exhibits non-markovian behavior as time revivals. This knowledge can aid the search for physical set-ups that best retain quantum properties under dissipative dynamics.

Floquet 修饰与热库谱效应对驱动耗散量子比特几何相位的影响

Floquet Dressing and Bath Spectral Effects on the Geometric Phase of a Driven Dissipative Qubit

本文用 PT-TEMPO 方法研究周期驱动对称自旋-玻色子模型的耗散几何相位，发现驱动可依时间尺度抑制或增强热库效应，并揭示 Floquet 谱调控主导耗散路径，为控制开放量子系统几何相位提供新手段。

Dissipative Floquet Dynamics: from Steady State to Measurement Induced Criticality in Trapped-ion Chains

Quantum systems evolving unitarily and subject to quantum measurements exhibit various types of non-equilibrium phase transitions, arising from the competition between unitary evolution and measurements. Dissipative phase transitions in steady states of time-independent Liouvillians and measurement induced phase transitions at the level of quantum trajectories are two primary examples of such transitions. Investigating a many-body spin system subject to periodic resetting measurements, we argue that many-body dissipative Floquet dynamics provides a natural framework to analyze both types of tr…

Enhancement of quantum correlations and geometric phase for a driven bipartite quantum system in a structured environment

We study the role of driving in an initial maximally entangled state evolving under the presence of a structured environment in a weak and strong regime. We focus on the enhancement and degradation of maximal Concurrence when the system is driven on and out of resonance for a general evolution, as well as the effect of adding a transverse coupling among the particles of the model. We further investigate the role of driving in the acquisition of a geometric phase for the maximally entangled state. As the model studied herein can be used to model experimental situations such as hybrid quantum cl…

驱动耗散自旋链中量子相变的特征

Signatures of Quantum Phase Transitions in Driven Dissipative Spin Chains

本文研究了驱动耗散自旋链中量子相变的特征，通过发展精确的分析方法，在耗散趋于零时揭示了稳态与淬火动力学的关联。

从规范到可调谐相图在开放量子长程系统中

From Canonical to Tunable Phase Diagrams in Open Quantum Long-Range Systems

研究广义LMG模型与热环境耦合的耗散动力学，先利用线性Lindblad主方程推导磁化方程并得到规范平衡相图，后扩展到非线性方程，发现跳跃保留参数可调控相图，建立了动力学与稳态行为联系，为工程非平衡相提供机制。

Quantum State and Process Tomography of Energy Transfer Systems via Ultrafast Spectroscopy

The description of excited state dynamics in multichromophoric systems constitutes both a theoretical and experimental challenge in modern physical chemistry. An experimental protocol which can systematically characterize both coherent and dissipative processes at the level of the evolving quantum state of the chromophores is desired. In this article, we show that a carefully chosen set of polarization controlled two-color heterodyned photon-echo experiments can be used to reconstruct the time-evolving density matrix of the one-exciton manifold of a heterodimer. This possibility in turn allows…