Open Fermi-Hubbard model: Landauer's vs. master equation approaches

Non-Markovian master equation for quantum transport of fermionic carriers

We propose a simple, yet feasible, model for quantum transport of fermionic carriers across tight-binding chain connecting two reservoirs maintained at arbitrary temperatures and chemical potentials. The model allows for elementary derivation of the master equation for the reduced single particle density matrix in a closed form in both Markov and Born approximations. In the Markov approximation the master equation is solved analytically, whereas in the Born approximation the problem is reduced to an algebraic equation for the single particle density matric in the Redfield form. The non-Markovi…

Quantum entanglement in the spatial symmetry breaking phase transition of a driven-dissipative Bose-Hubbard dimer

We theoretically explore quantum correlation properties of a dissipative Bose-Hubbard dimer in presence of a coherent drive. In particular, we focus on the regime where the semiclassical theory predicts a bifurcation with a spontaneous spatial symmetry breaking. The critical behavior in a well defined thermodynamical limit of large excitation numbers is considered and analyzed within a Gaussian approach. The case of a finite boson density is also examined by numerically integrating the Lindblad master equation for the density matrix. We predict the critical behavior around the bifurcation poin…

耗散玻色-哈伯德模型。方法和实例

The Dissipative Bose-Hubbard Model. Methods and Examples

开放多体量子系统在量子信息科学以及生物团簇和超冷原子气体的量子输运方面引起了新的兴趣。多粒子玻色子系统的物理相关性在于实现反直觉的输运现象和由于工程耗散而随机制备高度稳定和纠缠的多体状态。我们回顾了各种方法来描述一个开放的相互作用的超冷玻色子系统，可以模拟紧束缚哈伯德近似。随着理论和数值技术的介绍，我们提出了一系列的结果在不同的设置，基于主方程描述的耗散动力学的超冷玻色子在一维晶格。到目前为止，标准的数值方法，如精确解开的主方程的量子跳跃的小系统和超越平均场展开的较大的，我们提出了一个相干态路径积分形式主义的基础上，费曼弗农理论应用到多体上下文。

Two-Time Correlation Functions in Dissipative and Interacting Bose-Hubbard Chains

A method is presented for the systematic derivation of a hierarchy of coupled equations for the computation of two-time correlation functions of operators for open many-body quantum systems. We show how these systems of equations can be closed in mean-field and beyond approximations. Results for the specific example of the spectral weight functions are discussed. Our method allows one to access the full temporal evolution, not just the stationary solution, of non-equilibrium open quantum problems described by a Markovian master equation.

Generalized Lindblad Master Equation for Measurement-Induced Phase Transition

The measurement-induced phase transition (MIPT) occurs when the system is evolving under unitary evolution together with local measurements followed by post-selection. We propose a generalized version of the Lindblad master equation as a continuous equation, to describe the dynamics of second Rényi entropy in the MIPT. This generalized Lindblad equation explicitly takes into account the post-selection in the MIPT, which is realized as the Einstein-Podolsky-Rosen (EPR) state projection in the equation. Also, this generalized Lindblad equation preserves the Hermitian, unit trace, and positive de…

Extended Bose-Hubbard models with Rydberg macrodimer dressing

Extended Hubbard models have proven to bear novel quantum states, but their experimental realization remains challenging. In this work we propose to use bosonic quantum gases dressed with molecular bound states in Rydberg interaction potentials for the observation of these quantum states. We study the molecular Rabi coupling with respect to principal quantum number and trapping frequency of the ground state atoms for various molecular potentials of Rubidium and Potassium, and the hereby resulting dressed interaction strength. Additionally, we propose a two-color excitation scheme which signifi…