Related papers: Cairo lattice with time-reversal non-invariant vertex couplings

Cairo lattice with time-reversal non-invariant vertex couplings

URL: http://arxiv.org/abs/2312.13827v1
Date: Thu, 21 Dec 2023 13:18:07 GMT
Title: Cairo lattice with time-reversal non-invariant vertex couplings
Authors: Marzieh Baradaran and Pavel Exner
Abstract summary: We analyze the spectrum of a periodic quantum graph of the Cairo lattice form. We discuss two modifications of the model in which this is not the case. While different they both yield the same probability that a randomly chosen positive energy lies in the spectrum.
Score: 0.0
License: http://creativecommons.org/licenses/by/4.0/
Abstract: We analyze the spectrum of a periodic quantum graph of the Cairo lattice form. The used vertex coupling violates the time reversal invariance and its high-energy behavior depends on the vertex degree parity; in the considered example both odd and even parities are involved. The presence of the former implies that the spectrum is dominated by gaps. In addition, we discuss two modifications of the model in which this is not the case, the zero limit of the length parameter in the coupling, and the sign switch of the coupling matrix at the vertices of degree three; while different they both yield the same probability that a randomly chosen positive energy lies in the spectrum.

Related papers

Spectral properties of hexagonal lattices with the -R coupling [0.0]
We show that the spectral character does not change if the equilateral elementary cell of the lattice is dilated to have three different edge lengths, except that flat bands are absent if those are incommensurate. We also show that the spectral character does not change if the equilateral elementary cell of the lattice is dilated to have three different edge lengths, except that flat bands are absent if those are incommensurate.
arXiv Detail & Related papers (2024-09-05T13:55:57Z)
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)
Error bounds for Lie Group representations in quantum mechanics [44.99833362998488]
We provide state-dependent error bounds for strongly continuous unitary representations of Lie groups. Our method works for any connected Lie group and the metric is independent of the chosen representation.
arXiv Detail & Related papers (2022-11-15T23:55:53Z)
Non-Gaussian superradiant transition via three-body ultrastrong coupling [62.997667081978825]
We introduce a class of quantum optical Hamiltonian characterized by three-body couplings. We propose a circuit-QED scheme based on state-of-the-art technology that implements the considered model.
arXiv Detail & Related papers (2022-04-07T15:39:21Z)
Magnetic ring chains with vertex coupling of a preferred orientation [0.0]
We discuss spectral properties of an periodic quantum graph consisting of an array of rings coupled either tightly or loosely through connecting links. The magnetic field influences the probability that an energy belongs to the spectrum in the tight-chain case, and also it can turn some spectral bands into infinitely eigenvalues.
arXiv Detail & Related papers (2022-01-05T09:02:10Z)
Effect of Emitters on Quantum State Transfer in Coupled Cavity Arrays [48.06402199083057]
We study the effects of atoms in cavities which can absorb and emit photons as they propagate down the array. Our model is equivalent to previously examined spin chains in the one-excitation sector and in the absence of emitters.
arXiv Detail & Related papers (2021-12-10T18:52:07Z)
Probing many-body systems near spectral degeneracies [0.0]
diagonal elements of the time correlation matrix are used to probe closed quantum systems that are measured at random times. This separation is strongly affected when spectral degeneracies occur, for instance, in the presence of spontaneous symmetry breaking. Probing the quantum evolution with the diagonal elements of the time correlation matrix is discussed as a general concept and tested in the case of a bosonic Josephson junction.
arXiv Detail & Related papers (2021-08-30T12:02:33Z)
Spectrum of localized states in fermionic chains with defect and adiabatic charge pumping [68.8204255655161]
We study the localized states of a generic quadratic fermionic chain with finite-range couplings. We analyze the robustness of the connection between bands against perturbations of the Hamiltonian.
arXiv Detail & Related papers (2021-07-20T18:44:06Z)
Kagome network with vertex coupling of a preferred orientation [0.0]
We investigate spectral properties of periodic quantum graphs in the form of a kagome or a triangular lattice. The kagome lattice example shows that even in graphs with such an uncommon universality coupling spectral may hold.
arXiv Detail & Related papers (2021-06-30T12:35:12Z)
Spectrum of periodic chain graphs with time-reversal non-invariant vertex coupling [0.0]
We investigate spectral properties of quantum graphs in the form of a periodic chain of rings with a connecting link between each adjacent pair. We discuss the high-energy behavior of such systems and the limiting situations when one of the edges in the elementary cell of such a graph shrinks to zero.
arXiv Detail & Related papers (2020-12-28T16:35:45Z)
Equivalence of approaches to relational quantum dynamics in relativistic settings [68.8204255655161]
We show that the trinity' of relational quantum dynamics holds in relativistic settings per frequency superselection sector. We ascribe the time according to the clock subsystem to a POVM which is covariant with respect to its (quadratic) Hamiltonian.
arXiv Detail & Related papers (2020-07-01T16:12:24Z)

This list is automatically generated from the titles and abstracts of the papers in this site.