Resonant States of Wave Propagation in Disordered System of Bosonic Particles

无序多体系统中玻色子集体激发的二维光谱学

Two-dimensional spectroscopy of bosonic collective excitations in disordered many-body systems

提出基于 Keldysh 形式的非微扰理论方法计算无序多体系统玻色子集体激发的二维光谱，揭示回声峰区分散射过程的能力及量子涨落引发的多体效应。

Condensation versus Long-range Interaction: Competing Quantum Phases in Bosonic Optical Lattice Systems at Near-resonant Rydberg Dressing

Recent experiments have shown that (quasi-)crystalline phases of Rydberg-dressed quantum many-body systems in optical lattices (OL) are within reach. Rydberg systems naturally possess strong long-range interactions due to the large polarizability of Rydberg atoms. Thus a wide range of quantum phases have been predicted, such as a devil's staircase of lattice incommensurate density wave phases as well as more exotic lattice supersolid order for bosonic systems, as considered in our work. Guided by results in the "frozen" gas limit, we study the ground state phase diagram at finite hopping ampli…

确定性生成任意费米克态 via 共振子空间工程

Deterministic Generation of Arbitrary Fock States via Resonant Subspace Engineering

本文提出共振子空间工程方法，通过解析地限制玻色子动力学至二维子空间，实现高效率的确定性费米克态生成及多模平台的大规模态工程。

Bunching and anti-bunching of localised particles in disordered media

We consider pairs of non-interacting quantum particles transmitted through a disordered medium, with emphasis on the role of their quantum statistics. It is shown that particle-number correlations measured in transmission are strikingly sensitive to the quantum nature of the particles when they undergo Anderson localisation, due to bosonic bunching and fermionic anti-bunching in the scattering channels of the medium. The case of distinguishable particles is also discussed.

两种粒子玻色 Hubbard 模型中的多体局域化邻近效应

Many-body localization proximity effect in two-species bosonic Hubbard model

本文研究双组分玻色 Hubbard 模型中的 MBL 邻近效应，通过数值动力学模拟给出随耦合强度和热库尺寸变化的相图，并发现大热库导致整体退局域化及扩散输运。

Near-resonant light transmission in two-dimensional dense cold atomic media with short-range positional correlations

Light propagation in disordered media is a fundamental and important problem in optics and photonics. In particular, engineering light-matter interaction in disordered cold atomic ensembles is one of the central topics in modern quantum and atomic optics. The collective response of dense atomic gases under light excitation, which crucially depends on the spatial distribution of atoms and the geometry of the ensemble, has important impacts on quantum technologies like quantum sensors, atomic clocks and quantum information storage. Here we analyze near-resonant light transmission in two-dimensio…

Interaction-induced connectivity of disordered two-particle states

We study the interaction-induced connectivity in the Fock space of two particles in a disordered one-dimensional potential. Recent computational studies showed that the largest localization length $ξ_2$ of two interacting particles in a weakly random tight binding chain is increasing unexpectedly slow relative to the single particle localization length $ξ_1$, questioning previous scaling estimates. We show this to be a consequence of the approximate restoring of momentum conservation of weakly localized single particle eigenstates, and disorder-induced phase shifts for partially overlapping st…

AC-Conductivity Measure from Heat Production of Free Fermions in Disordered Media

We extend [Bru-de Siqueira Pedra-Hertling, J. Math. Phys. 56 (2015) 051901] in order to study the linear response of free fermions on the lattice within a (independently and identically distributed) random potential to a macroscopic electric field that is time- and space-dependent. We obtain the notion of a macroscopic AC-conductivity measure which only results from the second principle of thermodynamics. The latter corresponds here to the positivity of the heat production for cyclic processes on equilibrium states. Its Fourier transform is a continuous bounded function which is naturally call…

玻色玻璃相的量子气体显微镜与塔尔博干涉仪研究

Quantum-gas microscopy and Talbot interferometry of the Bose-glass phase

研究通过量子气体显微镜与塔尔博干涉仪测量玻色玻璃相的相干长度，利用单原子分辨探测和超冷原子在二维晶格中的有序势，揭示玻色玻璃相的特征，并观察非平衡动力学的迹象。

Designing Robust Quantum Refrigerators in Disordered Spin Models

We explore a small quantum refrigerator in which the working substance is made of paradigmatic nearest-neighbor quantum spin models, the XYZ and the XY model with Dzyaloshinskii-Moriya interactions, consisting of two and three spins, each of which is in contact with a bosonic bath. We identify a specific range of interaction strengths which can be tuned appropriately to ensure a cooling of the selected spin in terms of its local temperature in the weak-coupling limit. Moreover, we report that in this domain, when one of the interaction strengths is disordered, the performance of the thermal ma…

Stability of mobility edges in disordered interacting systems

Many-body localization provides a mechanism to avoid thermalization in isolated interacting quantum systems. The breakdown of thermalization may be complete, when all eigenstates in the many-body spectrum become localized, or partial, when the so-called many-body mobility edge separates localized and delocalized parts of the spectrum. Previously, De Roeck \textit{et al.}[arXiv:1506.01505] suggested a possible instability of the many-body mobility edge in energy density. The local ergodic regions -- so called "bubbles" -- resonantly spread throughout the system, leading to delocalization. In or…