Absence of superdiffusion in certain random spin models
- URL: http://arxiv.org/abs/2110.06951v1
- Date: Wed, 13 Oct 2021 18:00:06 GMT
- Title: Absence of superdiffusion in certain random spin models
- Authors: Pieter W. Claeys, Austen Lamacraft, Jonah Herzog-Arbeitman
- Abstract summary: The dynamics of spin at finite temperature in the spin-1/2 Heisenberg chain was found to be superdiffusive.
We show that operator dynamics in the strong noise limit at infinite temperature can be analyzed using perturbation theory as an expansion in $J$.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The dynamics of spin at finite temperature in the spin-1/2 Heisenberg chain
was found to be superdiffusive in numerous recent numerical and experimental
studies. Theoretical approaches to this problem have emphasized the role of
nonabelian SU(2) symmetry as well as integrability but the associated methods
cannot be readily applied when integrability is broken. We examine spin
transport in a spin-1/2 chain in which the exchange couplings fluctuate in
space and time around a nonzero mean $J$, a model introduced by De Nardis et
al. [Phys. Rev. Lett. 127, 057201 (2021)]. We show that operator dynamics in
the strong noise limit at infinite temperature can be analyzed using
conventional perturbation theory as an expansion in $J$. We find that regular
diffusion persists at long times, albeit with an enhanced diffusion constant.
The finite time spin dynamics is analyzed and compared with matrix product
operator simulations.
Related papers
- Emergent Continuous Time Crystal in Dissipative Quantum Spin System without Driving [1.641189223782504]
Time crystal, a nonequilibrium phenomenon extending spontaneous symmetry breaking into the temporal dimension, holds fundamental significance in quantum many-body physics.
We numerically identify the emergence of novel nonstationary oscillatory states by analyzing the spin dynamics.
This study provides many insights into the intricate interplay between the dissipation-induced spin downwards and anisotropic-interaction-induced spin precession or spin fluctuation.
arXiv Detail & Related papers (2024-03-13T12:40:32Z) - Superdiffusion from nonabelian symmetries in nearly integrable systems [0.0]
Heisenberg spin chain is a canonical integrable model.
Spin transport is sub-ballistic at any nonzero temperature.
Two-mode hydrodynamic description captures both the KPZ scaling of the correlation function and the coarse features of the full counting statistics.
arXiv Detail & Related papers (2023-05-24T18:00:00Z) - 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) - Slow semiclassical dynamics of a two-dimensional Hubbard model in
disorder-free potentials [77.34726150561087]
We show that introduction of harmonic and spin-dependent linear potentials sufficiently validates fTWA for longer times.
In particular, we focus on a finite two-dimensional system and show that at intermediate linear potential strength, the addition of a harmonic potential and spin dependence of the tilt, results in subdiffusive dynamics.
arXiv Detail & Related papers (2022-10-03T16:51:25Z) - Sufficient condition for gapless spin-boson Lindbladians, and its
connection to dissipative time-crystals [64.76138964691705]
We discuss a sufficient condition for gapless excitations in the Lindbladian master equation for collective spin-boson systems.
We argue that gapless modes can lead to persistent dynamics in the spin observables with the possible formation of dissipative time-crystals.
arXiv Detail & Related papers (2022-09-26T18:34:59Z) - Probing dynamics of a two-dimensional dipolar spin ensemble using single
qubit sensor [62.997667081978825]
We experimentally investigate individual spin dynamics in a two-dimensional ensemble of electron spins on the surface of a diamond crystal.
We show that this anomalously slow relaxation rate is due to the presence of strong dynamical disorder.
Our work paves the way towards microscopic study and control of quantum thermalization in strongly interacting disordered spin ensembles.
arXiv Detail & Related papers (2022-07-21T18:00:17Z) - Clean two-dimensional Floquet time-crystal [68.8204255655161]
We consider the two-dimensional quantum Ising model, in absence of disorder, subject to periodic imperfect global spin flips.
We show by a combination of exact diagonalization and tensor-network methods that the system can sustain a spontaneously broken discrete time-translation symmetry.
We observe a non-perturbative change in the decay rate of the order parameter, which is related to the long-lived stability of the magnetic domains in 2D.
arXiv Detail & Related papers (2022-05-10T13:04:43Z) - Entanglement and correlations in fast collective neutrino flavor
oscillations [68.8204255655161]
Collective neutrino oscillations play a crucial role in transporting lepton flavor in astrophysical settings.
We study the full out-of-equilibrium flavor dynamics in simple multi-angle geometries displaying fast oscillations.
We present evidence that these fast collective modes are generated by the same dynamical phase transition.
arXiv Detail & Related papers (2022-03-05T17:00:06Z) - Dynamics of Spin Helices in the One-Dimensional $XX$ Model [0.0]
We analytically study the dynamics of spin helices in the one-dimensional $XX$ model.
We find a separation of timescales between the in-plane and out-of-plane spin dynamics.
One of our key findings is that the spin correlation functions decay as $t-1/2$ at long time, in contrast to the experimentally observed exponential decay.
arXiv Detail & Related papers (2021-10-12T13:03:29Z) - Semiclassical dynamics of a disordered two-dimensional Hubbard model
with long-range interactions [0.0]
We analyze Quench dynamics in a two-dimensional system of interacting fermions.
For a weak and moderate disorder strength, we observe subdiffusive behavior of charges, while spins exhibit diffusive dynamics.
In contrast to the short-range model, strong inhomogeneities such as domain walls in the initial state can significantly slow down thermalization dynamics.
arXiv Detail & Related papers (2020-02-13T14:59:23Z) - Simulating fermions in spin-dependent potentials with spin models on an
energy lattice [0.0]
We study spin-1/2 fermions in spin dependent potentials under the emphspin model approximation.
We show that the spin model approximation is accurate for weak interactions.
We present numerical techniques that are useful for analysis of spin models on an energy lattice.
arXiv Detail & Related papers (2020-01-14T04:08:56Z)
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.