Dynamical Poles in Non-Hermitian Impurity Scattering
- URL: http://arxiv.org/abs/2604.12939v1
- Date: Tue, 14 Apr 2026 16:29:05 GMT
- Title: Dynamical Poles in Non-Hermitian Impurity Scattering
- Abstract summary: In Hermitian impurity scattering, each isolated late-time exponential is the fingerprint of a bound state.<n>We show that this correspondence breaks down in non-Hermitian bands.<n>Our results establish that the real-time analytic structure of the Green's function, not the static eigenvalue problem alone, organizes non-Hermitian impurity scattering.
- Score: 16.562827543427623
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: In Hermitian impurity scattering, each isolated late-time exponential is the fingerprint of a bound state. We show that this correspondence breaks down in non-Hermitian bands. For a single impurity in a non-Hermitian lattice, the late-time signal is controlled by isolated complex frequencies selected by the analytic continuation of the Green's function relevant to real-time dynamics, which we term dynamical poles (DPs). DPs need not coincide with static bound states: one may appear without any bound-state counterpart, while a static bound state may be dynamically invisible. The remainder of the signal is an incoherent background set by complex continuum edges. Our results establish that the real-time analytic structure of the Green's function, not the static eigenvalue problem alone, organizes non-Hermitian impurity scattering.
Related papers
- Finite-Time Node Separation in Recurrent Graph Neural Networks with Persistent Gaussian Perturbations [2.8427946758947304]
We provide a complementary finite-time analysis of the same persistent-noise architecture.<n>We first prove an exact second-moment decomposition for the expected squared distance between any two node representations.
arXiv Detail & Related papers (2026-09-12T13:06:41Z) - Incremental Aggregation on the Grassmannian for Asynchronous Eigenspace Computation [37.26483427088676]
We study asynchronous optimization for finite-sum eigenspace computation in heterogeneous distributed systems.<n>We propose a Grassmannian incremental aggregation method that refreshes only arriving components and reuses cached gradients.<n> Experiments on serial and distributed PCA demonstrate improved sample efficiency and wall-clock convergence over representative baselines.
arXiv Detail & Related papers (2026-08-05T03:21:38Z) - Disentangling Continuous-Time Latent Dynamics: Identifiability of Latent SDEs via Diffusion Shifts [60.95873409673775]
identifiability in continuous-time latent differential equation models remains largely open.<n>We study additive-noise latent SDEs observed through an unknown nonlinear diffeomorphism.<n>We propose a two-stage estimator for latent disentanglement and optional graph recovery.
arXiv Detail & Related papers (2026-06-26T16:18:28Z) - Entanglement complexification transition driven by a single non-Hermitian impurity [11.099898235432278]
We solve a Hermitian gapless chain with a single non-Hermitian impurity acting as a non-Hermitian boundary.<n>When the entanglement cut is placed at the impurity, we uncover a sharp emphentanglement complexification transition.<n>Our results reveal that a single non-Hermitian impurity can drive a Hermitian critical system into a nonunitary defect-CFT phase.
arXiv Detail & Related papers (2025-10-17T07:08:16Z) - Quantized decay charges in non-Hermitian networks characterized by directed graphs [6.921208208209727]
We introduce a new class of non-Hermitian systems exhibiting pure decay modes-eigenstates with pure, smooth exponential decay.<n>This discovery paves the way for potential applications in photonics, signal processing, and beyond.
arXiv Detail & Related papers (2025-07-15T13:54:03Z) - Flow based approach for Dynamic Temporal Causal models with non-Gaussian or Heteroscedastic Noises [37.02662517645979]
We introduce FANTOM, a unified framework for causal discovery.<n>It handles non-stationary processes along with non-Gaussian and heteroscedastic noises.<n>It simultaneously infers the number of regimes and their corresponding indices and learns each regime's Directed Acyclic Graph.
arXiv Detail & Related papers (2025-06-20T15:12:43Z) - Non-Hermitian topology and skin modes in the continuum via parametric processes [44.99833362998488]
We show that Hermitian, nonlocal parametric pairing processes can induce non-Hermitian topology and skin modes.<n>Our model, stabilized by local dissipation, reveals exceptional points that spawn a tilted diabolical line in the dispersion.
arXiv Detail & Related papers (2025-05-05T16:38:20Z) - Emulating non-Hermitian dynamics in a finite non-dissipative quantum system [0.0]
We discuss the emulation of non-Hermitian dynamics during a given time window.<n>We use a low-dimensional quantum system coupled to a finite set of equidistant discrete states acting as an effective continuum.<n>We show that such a continuum can reproduce non-Hermitian dynamics more efficiently than the usual quasi-continuum model.
arXiv Detail & Related papers (2025-02-04T17:24:07Z) - Fixed lines in a non-Hermitian Kitaev chain with spatially balanced
pairing processes [0.0]
Exact solutions for non-Hermitian quantum many-body systems are rare but may provide valuable insights into the interplay between Hermitian and non-Hermitian components.
We report our investigation of a non-Hermitian variant of a p-wave Kitaev chain by introducing staggered imbalanced pair creation and quench terms.
arXiv Detail & Related papers (2023-04-30T14:41:42Z) - 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) - Long-lived period-doubled edge modes of interacting and disorder-free
Floquet spin chains [68.8204255655161]
We show that even in the absence of disorder, and in the presence of bulk heating, $pi$ edge modes are long lived.
A tunneling estimate for the lifetime is obtained by mapping the stroboscopic time-evolution to dynamics of a single particle in Krylov subspace.
arXiv Detail & Related papers (2021-05-28T12:13:14Z) - The Connection between Discrete- and Continuous-Time Descriptions of
Gaussian Continuous Processes [60.35125735474386]
We show that discretizations yielding consistent estimators have the property of invariance under coarse-graining'
This result explains why combining differencing schemes for derivatives reconstruction and local-in-time inference approaches does not work for time series analysis of second or higher order differential equations.
arXiv Detail & Related papers (2021-01-16T17:11:02Z)
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.