Geometric phase of exceptional point as quantum resonance in complex scaling method
- URL: http://arxiv.org/abs/2512.24528v2
- Date: Wed, 07 Jan 2026 03:27:42 GMT
- Title: Geometric phase of exceptional point as quantum resonance in complex scaling method
- Authors: Okuto Morikawa, Shoya Ogawa, Soma Onoda,
- Abstract summary: We analyze the self-orthogonality in the vicinity of an EP, the Berry phase, and the Chern characteristic.<n>Our results provide a bridge between non-Hermitian spectral theory and the traditional theory of quantum resonances.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Non-Hermitian operators and exceptional points (EPs) are now routinely realized in few-mode systems such as optical resonators and superconducting qubits. However, their foundations in genuine scattering problems with unbounded Hamiltonians remain much less clear. In this work, we address how the geometric phase associated with encircling an EP should be formulated when the underlying eigenstates are quantum resonances within a one-dimensional scattering model. To do this, we employ the complex scaling method, where resonance poles of the S-matrix are realized as discrete eigenvalues of the non-Hermitian dilated Hamiltonian, to construct situations in which resonant and scattering states coalesce into an EP in the complex energy plane, that is, the resonance pole is embedded into the continuum spectrum. We analyze the self-orthogonality in the vicinity of an EP, the Berry phase, and the Chern characteristic. Our results provide a bridge between non-Hermitian spectral theory and the traditional theory of quantum resonances.
Related papers
- Controlling Excitation Localization in Waveguide QED Systems [0.4999814847776098]
We study localization and long-time population trapping in quantum emitters coupled to a waveguide.<n>We find two distinct mechanisms that give rise to localization: geometry-induced subradiance and disorder-induced Anderson-like confinement.<n>These results establish geometry and disorder as complementary tools for engineering long-lived quantum states in waveguide QED systems.
arXiv Detail & Related papers (2025-05-27T08:24:51Z) - Symmetries, Conservation Laws and Entanglement in Non-Hermitian Fermionic Lattices [37.69303106863453]
Non-Hermitian quantum many-body systems feature steady-state entanglement transitions driven by unitary dynamics and dissipation.<n>We show that the steady state is obtained by filling single-particle right eigenstates with the largest imaginary part of the eigenvalue.<n>We illustrate these principles in the Hatano-Nelson model with periodic boundary conditions and the non-Hermitian Su-Schrieffer-Heeger model.
arXiv Detail & Related papers (2025-04-11T14:06:05Z) - Nonlinear dynamical Casimir effect and Unruh entanglement in waveguide QED with parametrically modulated coupling [83.88591755871734]
We study theoretically an array of two-level qubits moving relative to a one-dimensional waveguide.
When the frequency of this motion approaches twice the qubit resonance frequency, it induces parametric generation of photons and excitation of the qubits.
We develop a comprehensive general theoretical framework that incorporates both perturbative diagrammatic techniques and a rigorous master-equation approach.
arXiv Detail & Related papers (2024-08-30T15:54:33Z) - Quantized Integrated Shift Effect in Multigap Topological Phases [0.0]
We recast the quantization in terms of the integrated torsion tensor and the non-Abelian Berry connection constituting Chern-Simons forms.
Our findings provide another quantized electromagnetic dc response due to the nontrivial band topology.
arXiv Detail & Related papers (2024-02-20T18:56:17Z) - Non-Hermiticity in quantum nonlinear optics through symplectic
transformations [0.0]
We show that second-quantised Hermitian Hamiltonians on the Fock space give rise to non-Hermitian effective Hamiltonians.
We create a quantum optical scheme for simulating arbitrary non-unitary processes by way of singular value decomposition.
arXiv Detail & Related papers (2023-10-06T18:41:46Z) - Dispersive Non-reciprocity between a Qubit and a Cavity [24.911532779175175]
We present an experimental study of a non-reciprocal dispersive-type interaction between a transmon qubit and a superconducting cavity.
We show that the qubit-cavity dynamics is well-described in a wide parameter regime by a simple non-reciprocal master-equation model.
arXiv Detail & Related papers (2023-07-07T17:19:18Z) - 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) - Quantum emulation of the transient dynamics in the multistate
Landau-Zener model [50.591267188664666]
We study the transient dynamics in the multistate Landau-Zener model as a function of the Landau-Zener velocity.
Our experiments pave the way for more complex simulations with qubits coupled to an engineered bosonic mode spectrum.
arXiv Detail & Related papers (2022-11-26T15:04:11Z) - Meson content of entanglement spectra after integrable and nonintegrable
quantum quenches [0.0]
We calculate the time evolution of the lower part of the entanglement spectrum and return rate functions after global quantum quenches in the Ising model.
Our analyses provide a deeper understanding on the role of quantum information quantities for the dynamics of emergent phenomena reminiscent to systems in high-energy physics.
arXiv Detail & Related papers (2022-10-27T18:00:01Z) - Probing the symmetry breaking of a light--matter system by an ancillary
qubit [50.591267188664666]
Hybrid quantum systems in the ultrastrong, and even more in the deep-strong, coupling regimes can exhibit exotic physical phenomena.
We experimentally observe the parity symmetry breaking of an ancillary Xmon artificial atom induced by the field of a lumped-element superconducting resonator.
This result opens a way to experimentally explore the novel quantum-vacuum effects emerging in the deep-strong coupling regime.
arXiv Detail & Related papers (2022-09-13T06:14:08Z) - Polariton Creation in Coupled Cavity Arrays with Spectrally Disordered Emitters [0.0]
Integrated photonics has been a promising platform for analog quantum simulation of condensed matter phenomena in strongly correlated systems.
We study energy band formation and wavefunction properties in the open quantum Tavis-Cummings-Hubbard framework.
New metrics combined with the Effective Hamiltonian approach prove to be a powerful toolbox for cavity quantum electrodynamical engineering of solid-state systems.
arXiv Detail & Related papers (2021-12-28T05:08:27Z) - Chiral Cavity Quantum Electrodynamics [0.0]
We explore for the first time cavity quantum electrodynamics of a transmon qubit in the topological vacuum of a Harper-Hofstadter topological lattice.
We spectroscopically resolve the individual bulk and edge modes of this lattice, detect vacuum-stimulated Rabi oscillations between the excited transmon and each mode, and thereby measure the synthetic-vacuum-induced Lamb shift of the transmon.
arXiv Detail & Related papers (2021-09-09T22:26:36Z) - Unraveling the topology of dissipative quantum systems [58.720142291102135]
We discuss topology in dissipative quantum systems from the perspective of quantum trajectories.
We show for a broad family of translation-invariant collapse models that the set of dark state-inducing Hamiltonians imposes a nontrivial topological structure on the space of Hamiltonians.
arXiv Detail & Related papers (2020-07-12T11:26:02Z)
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.