Characterizing entanglement by momentum-jump in the frustrated Heisenberg ring at quantum phase transition

Macroscopic entanglement jumps in model spin systems

In this paper, we consider some frustrated spin models for which the ground states are known exactly. The concurrence, a measure of the amount of entanglement can be calculated exactly for entangled spin pairs. Quantum phase transitions involving macroscopic magnetization changes at critical values of the magnetic field are accompanied by macroscopic jumps in the (T=0) entanglement. A specific example is given in which magnetization plateaus give rise to a plateau structure in the amount of entanglement associated with nearest-neighbour bonds. We further show that macroscopic entanglement chan…

受阻约瑟夫森结阵列中的集体量子相

Collective quantum phases in frustrated arrays of Josephson junctions

本研究探讨小型量子约瑟夫森结受阻锯齿阵列中的集体量子相及相变，通过阻挫参数控制势能复杂度，识别不同区域的量子相并利用局域磁化关联函数绘制相图，揭示其受多物理参数调控的规律。

由带拓扑约束的阻挫约瑟夫森结阵列涌现的长程伊辛自旋模型

Long-range Ising spins models emerging from frustrated Josephson junctions arrays with topological constraints

本研究理论分析带拓扑约束的阻挫约瑟夫森结Kagome晶格，推导长程各向异性伊辛自旋哈密顿量，揭示经典与量子区域的物相特征。

表面跳跃模拟中能量守恒动量跳变的第一性原理推导

A First Principles Derivation of Energy Conserving Momentum Jumps in Surface Hopping Simulations

本文从QTSH视角第一性原理推导FSSH的能量守恒动量跳变，并指出QTSH量子力可在系综层面严格守恒能量且无需人为动量重标度。

Quantum-jumps and photon-statistic in fluorescent systems coupled to classically fluctuating reservoirs

In this paper, we develop a quantum-jump approach for describing the photon-emission process of single fluorophore systems coupled to complex classically fluctuating reservoirs. The formalism relies on an open quantum system approach where the dynamic of the system and the reservoir fluctuations are described through a density matrix whose evolution is defined by a Lindblad rate equation. For each realization of the photon measurement processes it is possible to define a conditional system state (stochastic density matrix) whose evolution depends on both the photon detection events and the flu…

Local Kondo entanglement and its breakdown in an effective two-impurity Kondo model

Competition between the Kondo effect and Ruderman-Kittel-Kasuya-Yosida interaction in the two-impurity Kondo problem can be phenomenologically described by the Rasul-Schlottmann spin model. We revisit this model from the quantum entanglement perspective by calculating both the inter-impurity entanglement and the local Kondo entanglement, the latter being the entanglement between a local magnetic impurity and its spatially nearby conduction electron. A groundstate phase diagram is derived and a discontinuous breakdown of the local Kondo entanglement is found at the singular point, associated co…