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Related papers: Topological Transition in a Non-Hermitian Quantum …

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Non-interacting particles in non-Hermitian quasi crystals display localization-delocalization and spectral phase transitions in complex energy plane, that can be characterized by point-gap topology. Here we investigate the spectral and…

Quantum Physics · Physics 2025-04-10 Stefano Longhi

We predict the existence of non-Hermitian topologically protected end states in a one-dimensional exciton-polariton condensate lattice, where topological transitions are driven by the laser pump pattern. We show that the number of end…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Paolo Comaron , Vanik Shahnazaryan , Wojciech Brzezicki , Timo Hyart , Michał Matuszewski

Quantum walks are considered in a one-dimensional random medium characterized by static or dynamic disorder. Quantum interference for static disorder can lead to Anderson localization which completely hinders the quantum walk and it is…

Quantum Physics · Physics 2009-11-13 Yue Yin , D. E. Katsanos , S. N. Evangelou

There has been much recent interest and progress on topological structures of the non-Hermitian Bloch bands. Here, we study the topological structures of non-Bloch bands of non-Hermitian multiband quantum systems under open boundary…

Mesoscale and Nanoscale Physics · Physics 2024-09-10 Yongxu Fu , Yi Zhang

Multi-dimensional quantum walks can exhibit highly non-trivial topological structure, providing a powerful tool for simulating quantum information and transport systems. We present a flexible implementation of a 2D optical quantum walk on a…

The quantum walk is the quantum analogue of the well-known random walk, which forms the basis for models and applications in many realms of science. Its properties are markedly different from the classical counterpart and might lead to…

A $\mathcal{PT}$-symmetric, non-Hermitian Hamiltonian in the $\mathcal{PT}$-unbroken regime can lead to unitary dynamics under the appropriate choice of the Hilbert space. The Hilbert space is determined by a Hamiltonian-compatible inner…

Quantum Physics · Physics 2025-03-19 Himanshu Badhani , Subhashish Banerjee , C. M. Chandrashekar

We investigate the transport properties and entanglement between spin and position of one-dimensional quantum walks starting from a qubit over position states following a delta-like (local state) and Gaussian (delocalized state)…

Quantum Physics · Physics 2020-04-07 Henrique S. Ghizoni , Edgard P. M. Amorim

The development of non-Hermitian topological band theory has led to observations of novel topological phenomena in effectively classical, driven and dissipative systems. However, for open quantum many-body systems, the absence of a ground…

Mesoscale and Nanoscale Physics · Physics 2021-07-14 Sharareh Sayyad , Jinlong Yu , Adolfo G. Grushin , Lukas M. Sieberer

We give a topological classification of quantum walks on an infinite 1D lattice, which obey one of the discrete symmetry groups of the tenfold way, have a gap around some eigenvalues at symmetry protected points, and satisfy a mild locality…

Quantum Physics · Physics 2018-09-10 C. Cedzich , T. Geib , F. A. Grünbaum , C. Stahl , L. Velázquez , A. H. Werner , R. F. Werner

We study the localization transition in periodically driven one-dimensional non-Hermitian lattices where the piece-wise two-step drive is constituted by uniform coherent tunneling and incommensurate onsite gain and loss. We find that the…

Quantum Physics · Physics 2022-03-14 C. M. Dai , Yunbo Zhang , Xuexi Yi

We report on the theoretical investigation of the topological properties of a periodically quenched one-dimensional dimerized lattice where a piece-wise constant Hamiltonian switches from $h_1$ to $h_2$ at a partition time $t_p$ within each…

Mesoscale and Nanoscale Physics · Physics 2022-12-28 Milad Jangjan , Luis E. F. Foa Torres , Mir Vahid Hosseini

Non-Hermitian effects could trigger spectrum, localization and topological phase transitions in quasiperiodic lattices. We propose a non-Hermitian extension of the Maryland model, which forms a paradigm in the study of localization and…

Quantum Physics · Physics 2022-01-13 Longwen Zhou , Yongjian Gu

We investigate the two-component quantum walk in one-dimensional lattice. We show that the inter-component interaction strength together with the hopping imbalance between the components exhibit distinct features in the quantum walk for…

Quantum Gases · Physics 2021-11-15 Mrinal Kanti Giri , Suman Mondal , Bhanu Pratap Das , Tapan Mishra

We investigate the localization and topological transitions in a one-dimensional (interacting) non-Hermitian quasiperiodic lattice, which is described by a generalized Aubry-Andr\'{e}-Harper model with irrational modulations in the…

Quantum Physics · Physics 2021-03-31 Ling-Zhi Tang , Guo-Qing Zhang , Ling-Feng Zhang , Dan-Wei Zhang

The topology of one-dimensional chiral systems is captured by the winding number of the Hamiltonian eigenstates. Here we show that this invariant can be read-out by measuring the mean chiral displacement of a single-particle wavefunction…

We investigate the splitting probability of a monitored continuous-time quantum walk with two targets and show that, in stark contrast to a classical random walk, it exhibits a nonanalytic, phase-transition-like behavior controlled by the…

Statistical Mechanics · Physics 2026-01-23 Prashant Singh , David A. Kessler , Eli Barkai

We study the mechanism of decay of a topological (winding-number) excitation due to finite-size effects in a two-dimensional valence-bond solid state, realized in an $S=1/2$ spin model ($J$-$Q$ model) and studied using projector Monte Carlo…

Statistical Mechanics · Physics 2015-04-09 Hui Shao , Wenan Guo , Anders W. Sandvik

Exceptional point (EP) associated with eigenstates coalescence in non-Hermitian systems has many exotic features. The EPs are generally sensitive to system parameters, here we report symmetry protected isolated EPs in the Brillouin zone…

Quantum Physics · Physics 2019-05-07 S. Lin , L. Jin , Z. Song

A hallmark of topological band theory in periodic media is that bulk properties are not affected by boundary conditions. Remarkably, in certain non-Hermitian lattices the bulk properties are largely affected by boundaries, leading to such…

Optics · Physics 2020-12-15 Stefano Longhi