Magnetic field effects on the Kitaev model coupled to environment

• URL: http://arxiv.org/abs/2402.05516v2
• Date: Thu, 27 Jun 2024 08:16:00 GMT
• Title: Magnetic field effects on the Kitaev model coupled to environment
• Authors: Kiyu Fukui, Yasuyuki Kato, Yukitoshi Motome,
• Abstract summary: An effective non-Hermitian Kitaev model was shown to give rise to a gapless spin liquid state with exceptional points in the Majorana dispersions. We show that the exceptional points remain gapless up to a finite critical magnetic field, in stark contrast to the Hermitian case where an infinitesimal field opens a gap.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Open quantum systems display unusual phenomena not seen in closed systems, such as new topological phases and unconventional phase transitions. An interesting example was studied for a quantum spin liquid in the Kitaev model [K. Yang, S. C. Morampudi, and E. J. Bergholtz, Phys. Rev. Lett. ${\bf 126}$, 077201 (2021)]; an effective non-Hermitian Kitaev model, which incorporates dissipation effects, was shown to give rise to a gapless spin liquid state with exceptional points in the Majorana dispersions. Given that an external magnetic field induces a gapped Majorana topological state in the Hermitian case, the exceptional points may bring about intriguing quantum phenomena under a magnetic field. Here we investigate the non-Hermitian Kitaev model perturbed by the magnetic field. We show that the exceptional points remain gapless up to a finite critical magnetic field, in stark contrast to the Hermitian case where an infinitesimal field opens a gap. The gapless state is stable over a wide range of the magnetic field for some particular parameter sets, and in special cases, undergoes topological transitions to another gapless state with different winding number around the exceptional points without opening a gap. In addition, in the system with edges, we find that the non-Hermitian skin effect is induced by the magnetic field, even for the parameters where the skin effect is absent at zero field. The chirality of edge states is switched through the exceptional points, similarly to the surface Fermi arcs connected by the Weyl points in three-dimensional Weyl semimetals. Our results provide a new possible route to stabilize topological gapless quantum spin liquids under the magnetic field in the presence of dissipation.

Related papers

• Crossing exceptional points in non-Hermitian quantum systems [41.94295877935867]
  We reveal the behavior of two-photon quantum states in non-Hermitian systems across the exceptional point. We demonstrate a switching in the quantum interference of photons directly at the exceptional point.
  arXiv  Detail & Related papers  (2024-07-17T14:04:00Z)
• Emergent Majorana metal from a chiral spin liquid [50.56734933757366]
  We propose a novel mechanism to explain the emergence of an intermediate gapless spin liquid phase (IGP) in the antiferromagnetic Kitaev model. We show that the Majorana spectral function captures the dynamical spin and dimer correlations obtained by the infinite Projectedangled Pair States (iPEPS) an Entsatz.
  arXiv  Detail & Related papers  (2024-05-20T18:00:01Z)
• Ferrimagnetism of ultracold fermions in a multi-band Hubbard system [34.95884242542007]
  We report on signatures of a ferrimagnetic state realized in a Lieb lattice at half-filling. We demonstrate its robustness when increasing repulsive interactions from the non-interacting to the Heisenberg regime. Our work paves the way towards exploring exotic phases in related multi-orbital models such as quantum spin liquids in kagome lattices and heavy fermion behavior in Kondo models.
  arXiv  Detail & Related papers  (2024-04-26T17:33:26Z)
• Competing topological phases in a non-Hermitian time-reversal symmetry-broken Bernevig-Hughes-Zhang model [0.0]
  We show that the inclusion of a spin-dependent non-Hermitian balanced gain/loss potential induces a competition between these first and second-order topological phases. Surprisingly, the previously dormant first-order helical edge states in the nanoribbon resurface as the non-Hermitian effect intensifies.
  arXiv  Detail & Related papers  (2024-04-05T15:57:16Z)
• Recognizing critical lines via entanglement in non-Hermitian systems [0.0]
  We show that the non-Hermitian model can be an effective Hamiltonian of a Hermitian XX spin-1/2 with KSEA interaction and a local magnetic field. We demonstrate that the nearest-neighbor entanglement and its derivative can identify quantum critical lines with the variation of the magnetic field.
  arXiv  Detail & Related papers  (2023-05-15T06:20:56Z)
• Relativistic Landau quantization in non-uniform magnetic field and its applications to white dwarfs and quantum information [0.0]
  We find that the degeneracy of Landau levels, which arises in the case of the constant magnetic field, lifts out when the field is variable. Also the varying magnetic field splits Landau levels of electrons with zero angular momentum from positive angular momentum, unlike the constant field which only can split the levels between positive and negative angular momenta.
  arXiv  Detail & Related papers  (2021-10-18T18:00:06Z)
• Phase diagram of a distorted kagome antiferromagnet and application to Y-kapellasite [50.591267188664666]
  We reveal a rich ground state phase diagram even at the classical level. The presented model opens a new direction in the study of kagome antiferromagnets.
  arXiv  Detail & Related papers  (2021-07-28T18:00:03Z)
• Non-equilibrium stationary states of quantum non-Hermitian lattice models [68.8204255655161]
  We show how generic non-Hermitian tight-binding lattice models can be realized in an unconditional, quantum-mechanically consistent manner. We focus on the quantum steady states of such models for both fermionic and bosonic systems.
  arXiv  Detail & Related papers  (2021-03-02T18:56:44Z)
• Defective Majorana zero modes in non-Hermitian Kitaev chain [0.9786690381850356]
  Topological stability is an important property for topological materials. Non-Hermitian effects may change this situation. Novel non-Hermitian effects offer fresh insights into MZMs and topological physics.
  arXiv  Detail & Related papers  (2020-10-22T05:20:54Z)
• Majorana bound states in topological insulators with hidden Dirac points [25.488181126364186]
  We show that well-defined Majorana bound states can be obtained even in materials with hidden Dirac point. The obtained topological phase diagram allows one to extract precisely the position of the Dirac point in the spectrum.
  arXiv  Detail & Related papers  (2020-04-22T15:04:39Z)
• Observation of the Anomalous Hall Effect in a Collinear Antiferromagnet [8.779987820381487]
  Time-reversal breaking is the basic physics concept underpinning many magnetic topological phenomena. A potential breakthrough is the recent theoretical prediction of the AHE arising from collinear antiferromagnetism. Our results open a new unexplored chapter of time-reversal symmetry breaking phenomena in the abundant class of collinear antiferromagnetic materials.
  arXiv  Detail & Related papers  (2020-02-20T12:55:31Z)

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.