Robust symmetry breaking in gapless quantum magnets

• URL: http://arxiv.org/abs/2603.13212v1
• Date: Fri, 13 Mar 2026 17:48:27 GMT
• Title: Robust symmetry breaking in gapless quantum magnets
• Abstract summary: We prove the existence of spontaneous symmetry breaking in suitably low-energy eigenstates of certain gapless quantum systems.<n>Our work represents a first step towards a rigorous classification of stable gapless quantum phases.
• Score: 1.5036675956983638
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We prove the existence of spontaneous symmetry breaking in suitably low-energy eigenstates of certain gapless and frustrated many-body quantum systems, namely symmetric quantum perturbations to classical models which exhibit spontaneous symmetry breaking of a finite group at some positive temperature. Additionally, the classical model need not be local in space, as long as it satisfies a quantum analogue of the Peierls condition. As an example of our technique, we establish robust ferromagnetism in random-bond Ising models in $d= 2$ dimensions with sufficiently biased random couplings, with weak transverse field. Our mathematical technique is based on establishing quantum bottlenecks, similar to a "many-body WKB" method for evaluating tunneling rates. Using these same methods, we provide new proofs of metastability and the slow decay of the false vacuum, applicable to gapless metastable states. Our work represents a first step towards a rigorous classification of stable gapless quantum phases.

Related papers

• Symmetry Constrained Quantum Error Mitigation for the Schwinger Model [39.146761527401424]
  We exploit the parity and fermion-number symmetries of a gauge theory under depolarising noise.<n>We investigate symmetry verification under digital quantum simulation.
  arXiv  Detail & Related papers  (2026-08-21T13:49:11Z)
• Quantum optomechanics of lossy bodies: general approach and structured squeezed vacuum effects [51.56484100374058]
  We investigate the overall optomechanical force experienced by a macroscopic lossy object in free space under external quantum illumination.<n>By driving the scattering field with an anisotropic, multimode squeezed vacuum state, the spatial profile of the electromagnetic quantum fluctuations can be engineered to exhibit broken rotational symmetry.<n>We establish a general formalism for macroscopic quantum optomechanics that operates beyond the constraints of thermal equilibrium.
  arXiv  Detail & Related papers  (2026-04-07T13:25:43Z)
• Hybrid quantum-classical analog simulation of two-dimensional Fermi-Hubbard models with neutral atoms [28.672618404356474]
  We experimentally study the two-dimensional Fermi-Hubbard model using a Rydberg-based quantum processing unit in the analog mode.<n>Our approach avoids encoding directly the original fermions into qubits.<n>We then introduce the auxiliary spin solver.
  arXiv  Detail & Related papers  (2025-10-07T13:06:41Z)
• Path integral approach to quantum thermalization [39.25860941747971]
  We introduce a quasiclassical Green function approach describing the unitary yet irreversible dynamics of quantum systems.<n>We show that it is capable of describing a wide range of system classes and disorder models.<n>We present our formalism in a self-contained and pedagogical manner, aiming to provide a transferable toolbox for the first-principles description of many-body chaotic quantum systems.
  arXiv  Detail & Related papers  (2025-09-07T12:10:48Z)
• Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies [44.1973928137492]
  We show that chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits.<n>Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.
  arXiv  Detail & Related papers  (2025-01-21T08:23:12Z)
• Stable infinite-temperature eigenstates in SU(2)-symmetric nonintegrable models [0.0]
  A class of nonintegrable bond-staggered models is endowed with a large number of zero-energy eigenstates and possesses a non-Abelian internal symmetry.<n>We show that few-magnon zero-energy states have an exact analytical description, allowing us to build a basis of low-entangled fixed-separation states.
  arXiv  Detail & Related papers  (2024-07-16T17:48:47Z)
• Edge modes and symmetry-protected topological states in open quantum systems [0.0]
  Topological order offers possibilities for processing quantum information which can be immune to imperfections.<n>We utilize this robustness against a wide class of dissipation channels in the Lindblad and quantum formalisms of an open quantum system.<n>Our work thus proposes a novel framework to study the dynamics of dissipative SPT phases and opens the possibility of engineering entangled states relevant to quantum information processing.
  arXiv  Detail & Related papers  (2023-10-13T21:09:52Z)
• Quantum nonreciprocal interactions via dissipative gauge symmetry [18.218574433422535]
  One-way nonreciprocal interactions between two quantum systems are typically described by a cascaded quantum master equation. We present a new approach for obtaining nonreciprocal quantum interactions that is completely distinct from cascaded quantum systems.
  arXiv  Detail & Related papers  (2022-03-17T15:34:40Z)
• Many-body Hilbert space scarring on a superconducting processor [19.205729719781548]
  Quantum many-body scarring (QMBS) is a recently discovered form of weak ergodicity breaking in strongly-interacting quantum systems. Here, we experimentally realize a distinct kind of QMBS phenomena by approximately decoupling a part of the many-body Hilbert space in the computational basis. Our experimental findings broaden the realm of QMBS mechanisms and pave the way to exploiting correlations in QMBS states for applications in quantum information technology.
  arXiv  Detail & Related papers  (2022-01-10T16:33:38Z)
• Quantifying fermionic nonlinearity of quantum circuits [0.5658123802733283]
  We quantify the classical simulatability of quantum circuits designed for simulating fermionic Hamiltonians. We find that, depending on the error probability and atomic spacing, there are regions where the fermionic nonlinearity becomes very small or unity.
  arXiv  Detail & Related papers  (2021-11-29T15:31:43Z)
• Enhanced nonlinear quantum metrology with weakly coupled solitons and particle losses [58.720142291102135]
  We offer an interferometric procedure for phase parameters estimation at the Heisenberg (up to 1/N) and super-Heisenberg scaling levels. The heart of our setup is the novel soliton Josephson Junction (SJJ) system providing the formation of the quantum probe. We illustrate that such states are close to the optimal ones even with moderate losses.
  arXiv  Detail & Related papers  (2021-08-07T09:29:23Z)
• 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)
• Dynamical Mean-Field Theory for Markovian Open Quantum Many-Body Systems [0.0]
  We extend the nonequilibrium bosonic Dynamical Mean Field Theory to Markovian open quantum systems. As a first application, we address the steady-state of a driven-dissipative Bose-Hubbard model with two-body losses and incoherent pump.
  arXiv  Detail & Related papers  (2020-08-06T10:35:26Z)

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.