Distribution of fidelity zeros in two-band topological models

• URL: http://arxiv.org/abs/2603.18592v1
• Date: Thu, 19 Mar 2026 07:58:23 GMT
• Title: Distribution of fidelity zeros in two-band topological models
• Abstract summary: We investigate the distribution of fidelity zeros in two-band topological models.<n>We reveal that fidelity zeros are related to momentum modes for which the real part of the energy gap vanishes.
• Score: 2.0766567555304154
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate the distribution of fidelity zeros in two-band topological models by extending the phase transition driving parameter into the complex plane. Within the biorthogonal formulation, we unveil that fidelity zeros are related to momentum modes for which the real part of the energy gap vanishes. Guided by this relation, we analyze the Kitaev chain, the Haldane model, and the Qi-Wu-Zhang (QWZ) model. In finite-size systems the zeros form discrete lines parallel to the imaginary axis, while in the thermodynamic limit they accumulate into extended regions in the complex parameter plane. For the Kitaev and Haldane models, the accessible interval of the real part of the complexified parameter is bounded by the critical points of the corresponding topological transitions. For the QWZ model, the transitions at $u = \pm2$ are identified in the same way, whereas the critical point at $u = 0$ is signaled by fidelity zeros crossing the real axis. These results extend the fidelity-zero framework to topological quantum phase transitions and clarify how critical information is encoded in complexified parameter space.

Related papers

• Tracing complex zeros of the quantum survival amplitude: How the energy distribution controls dynamical phase transitions [0.0]
  We show that the large-scale properties of the distribution of zeros are governed by the envelope of the energy distribution of the initial state.<n>We prove that the approximate construction becomes exact for BCS ground-state quenches in two-band models.<n>Our results identify the energy envelope as the key ingredient shaping dynamical critical behavior.
  arXiv  Detail & Related papers  (2026-05-07T18:51:28Z)
• Exactly Solvable RD Model: RG Cycles Meet Fractality [45.88028371034407]
  We consider the Bethe ansatz integrable Russian Doll (RD) model of superconductivity with time-reversal symmetry breaking.<n>By obtaining an exact solution for the renormalization group flows, we investigate the phase structure in the one-pair sector.<n>We show that the quantum number Q, arising from the Bethe ansatz equations, counts the number of cycles and parametrizes the towers of states.
  arXiv  Detail & Related papers  (2026-03-18T12:54:21Z)
• Symmetry-protected topology and deconfined solitons in a multi-link $\mathbb{Z}_2$ gauge theory [45.88028371034407]
  We study a $mathbbZ$ lattice gauge theory defined on a multi-graph with links that can be visualized as great circles of a spherical shell.<n>We show that this leads to state-dependent tunneling amplitudes underlying a phenomenon analogous to the Peierls instability.<n>By performining a detailed analysis based on matrix product states, we prove that charge deconfinement emerges as a consequence of charge-fractionalization.
  arXiv  Detail & Related papers  (2026-03-02T22:59:25Z)
• Symmetry and Topology in the Non-Hermitian Kitaev chain [1.4273866043218153]
  We study the non-Hermitian Kitaev chain with non-reciprocal hopping amplitudes and asymmetric superconducting pairing.<n>We show that particle-hole symmetry (PHS) is preserved throughout the entire parameter regime.<n>We present the topological phase diagram of the non-Hermitian Kitaev chain across a broad range of complex parameters.
  arXiv  Detail & Related papers  (2026-01-02T19:00:02Z)
• From Chern to Winding: Topological Invariant Correspondence in the Reduced Haldane Model [0.4249842620609682]
  We present an exact analytical investigation of the topological properties and edge states of the Haldane model defined on a honeycomb lattice with zigzag edges.<n>We show that the $nu$ exactly reproduces the Chern number of the parent model in the topologically nontrivial phase.<n>Our analysis further reveals the critical momentum $ k_c $ where edge states traverse the bulk energy gap.
  arXiv  Detail & Related papers  (2025-05-26T19:11:43Z)
• Critical spin models from holographic disorder [49.1574468325115]
  We study the behavior of XXZ spin chains with a quasiperiodic disorder not present in continuum holography.<n>Our results suggest the existence of a class of critical phases whose symmetries are derived from models of discrete holography.
  arXiv  Detail & Related papers  (2024-09-25T18:00:02Z)
• Interactions and Topology in Quantum Matter: Auxiliary Field Approach & Generalized SSH Models [0.0]
  This thesis presents a set of projects which lie at the intersection between strong correlations and topological phases of matter. The first of these projects is a treatment of an infinite dimensional generalization of the SSH model with local Coulomb interactions which is solved exactly using DMFT-NRG. The second set of projects involves the development of methods for formulating non-interacting auxiliary models for strongly correlated systems.
  arXiv  Detail & Related papers  (2022-12-09T18:38:31Z)
• Disentanglement, disorder lines, and Majorana edge states in a solvable quantum chain [0.0]
  The model has three known gapped phases with local and nonlocal (string) orders, along with the gapless incommensurate (IC) phase in the $U(1)$ limit. The analysis of those roots yields the phase diagram which contains continuous quantum phase transitions and weaker singularities known as disorder lines (DLs) or modulation transitions. The salient property of zeros of the spectrum is that the ground state is shown to be separable (factorized) and the model is disentangled on a subset of the DLs.
  arXiv  Detail & Related papers  (2022-07-04T00:16:08Z)
• Topological transitions with continuously monitored free fermions [68.8204255655161]
  We show the presence of a topological phase transition that is of a different universality class than that observed in stroboscopic projective circuits. We find that this entanglement transition is well identified by a combination of the bipartite entanglement entropy and the topological entanglement entropy.
  arXiv  Detail & Related papers  (2021-12-17T22:01:54Z)
• Exact thermal properties of free-fermionic spin chains [68.8204255655161]
  We focus on spin chain models that admit a description in terms of free fermions. Errors stemming from the ubiquitous approximation are identified in the neighborhood of the critical point at low temperatures.
  arXiv  Detail & Related papers  (2021-03-30T13:15:44Z)
• Tuning the topology of $p$-wave superconductivity in an analytically solvable two-band model [0.0]
  We introduce and solve a two-band model of spinless fermions with $p_x$-wave pairing on a square lattice. We show that its phase diagram contains a topologically nontrivial weak pairing phase as well as a trivial strong pairing phase.
  arXiv  Detail & Related papers  (2020-10-01T01:20:46Z)
• From stochastic spin chains to quantum Kardar-Parisi-Zhang dynamics [68.8204255655161]
  We introduce the asymmetric extension of the Quantum Symmetric Simple Exclusion Process. We show that the time-integrated current of fermions defines a height field which exhibits a quantum non-linear dynamics.
  arXiv  Detail & Related papers  (2020-01-13T14:30:36Z)

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.