Geometric phase from encircling an exceptional point of a quantum resonance in the complex-scaling method

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Morikawa, Okuto, Ogawa, Shoya, Onoda, Soma
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866916048398188544
author Morikawa, Okuto
Ogawa, Shoya
Onoda, Soma
author_facet Morikawa, Okuto
Ogawa, Shoya
Onoda, Soma
contents Non-Hermitian operators are now routinely used to describe few-mode systems such as optical resonators and superconducting qubits, and exceptional points (EPs) are defective spectral singularities of such non-Hermitian operators. In contrast, the scattering-theoretic formulation of EP physics for unbounded Hamiltonians remains less settled. In this work, we formulate the geometric phase associated with encircling an EP 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 clarify how EP branch structure and geometric holonomy arise directly from resonance poles in scattering theory, thereby connecting non-Hermitian spectral topology with the traditional theory of quantum resonances.
format Preprint
id arxiv_https___arxiv_org_abs_2512_24528
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Geometric phase from encircling an exceptional point of a quantum resonance in the complex-scaling method
Morikawa, Okuto
Ogawa, Shoya
Onoda, Soma
Quantum Physics
High Energy Physics - Theory
Nuclear Theory
Non-Hermitian operators are now routinely used to describe few-mode systems such as optical resonators and superconducting qubits, and exceptional points (EPs) are defective spectral singularities of such non-Hermitian operators. In contrast, the scattering-theoretic formulation of EP physics for unbounded Hamiltonians remains less settled. In this work, we formulate the geometric phase associated with encircling an EP 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 clarify how EP branch structure and geometric holonomy arise directly from resonance poles in scattering theory, thereby connecting non-Hermitian spectral topology with the traditional theory of quantum resonances.
title Geometric phase from encircling an exceptional point of a quantum resonance in the complex-scaling method
topic Quantum Physics
High Energy Physics - Theory
Nuclear Theory
url https://arxiv.org/abs/2512.24528