Alternating quantum-emitter chains: Exceptional-point phase transition,
edge state, and quantum walks
- URL: http://arxiv.org/abs/2305.16059v1
- Date: Thu, 25 May 2023 13:45:30 GMT
- Title: Alternating quantum-emitter chains: Exceptional-point phase transition,
edge state, and quantum walks
- Authors: Jimin Li and Zongping Gong
- Abstract summary: We study the long-range hopping limit of a one-dimensional array of $N$ equal-distanced quantum emitters in free space.
For two species of emitters in an alternating arrangement, the single excitation sector exhibits non-Hermitian spectral singularities known as exceptional points.
We unveil an unconventional phase transition, dubbed exceptional-point phase transition, from the collective to individual spontaneous emission behaviors.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We study the long-range hopping limit of a one-dimensional array of $N$
equal-distanced quantum emitters in free space, where the hopping amplitude of
emitter excitation is proportional to the inverse of the distance and equals
the lattice dimension. For two species of emitters in an alternating
arrangement, the single excitation sector exhibits non-Hermitian spectral
singularities known as exceptional points. We unveil an unconventional phase
transition, dubbed exceptional-point phase transition, from the collective to
individual spontaneous emission behaviors. At the transition point, the $N
\times N$ Hamiltonian fragments into $N/2-1$ many two-dimensional
non-diagonalizable blocks. The remaining diagonalizable block contains a
dissipation-induced edge state with algebraically localized profiles, and we
provide numerical evidence for its existence in the infinite-array limit. We
demonstrate that the edge state can be eliminated via a continuous deformation,
consistent with the ill-definedness of bulk topological invariant. We also
propose a spatially resolved character to quantify the incoherent flow and loss
in the non-unitary quantum walks of single atomic excitations.
Related papers
- Quantum Random Walks and Quantum Oscillator in an Infinite-Dimensional Phase Space [45.9982965995401]
We consider quantum random walks in an infinite-dimensional phase space constructed using Weyl representation of the coordinate and momentum operators.
We find conditions for their strong continuity and establish properties of their generators.
arXiv Detail & Related papers (2024-06-15T17:39:32Z) - Theory of free fermions dynamics under partial post-selected monitoring [49.1574468325115]
We derive a partial post-selected Schrdinger"o equation based on a microscopic description of continuous weak measurement.
We show that the passage to the monitored universality occurs abruptly at finite partial post-selection.
Our approach establishes a way to study MiPTs for arbitrary subsets of quantum trajectories.
arXiv Detail & Related papers (2023-12-21T16:53:42Z) - Multipartite Entanglement in the Measurement-Induced Phase Transition of
the Quantum Ising Chain [77.34726150561087]
External monitoring of quantum many-body systems can give rise to a measurement-induced phase transition.
We show that this transition extends beyond bipartite correlations to multipartite entanglement.
arXiv Detail & Related papers (2023-02-13T15:54:11Z) - Measurement phase transitions in the no-click limit as quantum phase
transitions of a non-hermitean vacuum [77.34726150561087]
We study phase transitions occurring in the stationary state of the dynamics of integrable many-body non-Hermitian Hamiltonians.
We observe that the entanglement phase transitions occurring in the stationary state have the same nature as that occurring in the vacuum of the non-hermitian Hamiltonian.
arXiv Detail & Related papers (2023-01-18T09:26:02Z) - Triviality of quantum trajectories close to a directed percolation
transition [0.0]
We study quantum circuits consisting of unitary gates, projective measurements, and control operations that steer the system towards a pure absorbing state.
Two types of phase transition occur as the rate of these control operations is increased: a measurement-induced entanglement transition, and a directed percolation transition into the absorbing state.
arXiv Detail & Related papers (2022-12-28T18:52:56Z) - Superdiffusion in random two dimensional system with time-reversal symmetry and long-range hopping [45.873301228345696]
localization problem in the crossover regime for the dimension $d=2$ and hopping $V(r) propto r-2$ is not resolved yet.
We show that for the hopping determined by two-dimensional anisotropic dipole-dipole interactions there exist two distinguishable phases at weak and strong disorder.
arXiv Detail & Related papers (2022-05-29T16:53:20Z) - Exceptional Spectral Phase in a Dissipative Collective Spin Model [0.0]
We name normal and exceptional Liouvillian spectral phases.
In the thermodynamic limit, the exceptional spectral phase displays the unique property of being made up exclusively of second order exceptional points.
This criticality is transferred onto the steady state, implying a dissipative quantum phase transition and the formation of a boundary time crystal.
arXiv Detail & Related papers (2022-02-18T18:05:23Z) - Quantum Entanglement of Non-Hermitian Quasicrystals [7.371841894852217]
We present a class of experimentally realizable models for non-Hermitian quasicrystal chains.
We numerically determine the metal-insulator transition point.
Inspired by entanglement spectrum, we further analytically prove that a duality exists between the two phase regions.
arXiv Detail & Related papers (2021-12-26T16:17:04Z) - Quasistationary states in a quantum dot formed at the edge of a
topological insulator by magnetic barriers with finite transparency [0.0]
A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well.
The lifetimes of these quasistationary states are found analytically and numerically via different approaches.
arXiv Detail & Related papers (2021-12-17T11:56:51Z) - Radiative topological biphoton states in modulated qubit arrays [105.54048699217668]
We study topological properties of bound pairs of photons in spatially-modulated qubit arrays coupled to a waveguide.
For open boundary condition, we find exotic topological bound-pair edge states with radiative losses.
By joining two structures with different spatial modulations, we find long-lived interface states which may have applications in storage and quantum information processing.
arXiv Detail & Related papers (2020-02-24T04:44:12Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.