Isolated Heisenberg magnet as a quantum time crystal

@article{Medenjak2020IsolatedHM,
  title={Isolated Heisenberg magnet as a quantum time crystal},
  author={Marko Medenjak and Berislav Bu{\vc}a and Dieter Jaksch},
  journal={Physical Review B},
  year={2020},
  volume={102},
  pages={041117}
}
Local observables of closed many-body quantum systems are generally believed to quickly equilibrate after a quench, according to the eigenstate thermalization hypothesis. Here, the authors show that the paradigmatic Heisenberg quantum magnet violates this fundamental assumption. They analytically find measurable local correlation functions that show perpetual oscillations, while at the same time all single-particle observables equilibrate. They link their existence to the presence of dynamical… 

Figures from this paper

Quantum Time Crystals from Hamiltonians with Long-Range Interactions.
TLDR
This study proposes a form of a Hamiltonian for which the unitary dynamics exhibits the time crystalline behavior and breaks continuous TTS, based on a spin-1/2 many-body Hamiltonian which has long-range multispin interactions in the form of spin strings, thus bypassing previously known no-go theorems.
Measurement catastrophe and ballistic spread of charge density with vanishing current
One of the features of many-body quantum systems with Hilbert-space fragmentation are stationary states manifesting quantum jamming. It was recently shown that these are “states with memory”, in
Ju l 2 01 9 Continuous time crystals from static Hamiltonians with long-range interactions
Time crystals correspond to a phase of matter where time-translational symmetry (TTS) is broken. Up to date, they are well studied in open quantum systems, where external drive allows to break
Reply to "Comment on "Quantum Time Crystals from Hamiltonians with Long-Range Interactions""
In the note by Khemani et al. [arXiv:2001.11037] the authors express conceptual disagreement with our recent paper on quantum time crystals [Phys. Rev. Lett. 123, 210602]. They criticise the
Exotic equilibration dynamics on a 1-D quantum CNOT gate lattice
We consider the dynamics of local entropy and nearest neighbor mutual information of a 1-D lattice of qubits via the repeated application of nearest neighbor CNOT quantum gates. This is a quantum
Quantum synchronisation enabled by dynamical symmetries and dissipation
In nature, instances of synchronisation abound across a diverse range of environments. In the quantum regime, however, synchronisation is typically observed by identifying an appropriate parameter
Operator thermalization vs eigenstate thermalization
We study the characteristics of thermalizing and non-thermalizing operators in integrable theories as we turn on a non-integrable deformation. Specifically, we show that $\sigma^z$, an operator that
Generalized criteria of symmetry breaking. A strategy for quantum time crystals
The aim of this paper is to propose a criterion of spontaneous symmetry breaking that makes reference to the properties of pure phases defined by a translationally invariant state. By avoiding any
Thermalization/Relaxation in integrable and free field theories: an Operator Thermalization Hypothesis
Free or integrable theories are usually considered to be too constrained to thermalize. For example, the retarded two-point function of a free field, even in a thermal state, does not decay to zero
Nonequilibrium physics in integrable systems and spin-flip non-invariant conserved quantities
Recently found spin-flip non-invariant conserved quantities play important roles in discussing nonequilibrium physics of the XXZ model. The representative examples are the generalized Gibbs ensemble
...
1
2
3
4
...

References

SHOWING 1-10 OF 108 REFERENCES
Strongly correlated fermions after a quantum quench.
TLDR
This work studies the time evolution of strongly correlated spinless fermions on a one-dimensional lattice after a sudden change of the interaction strength and finds that the resulting quasistationary state is nonthermal.
Periodic thermodynamics of isolated quantum systems.
TLDR
It is analytically show that, for a class of integrable systems, the relevant ensemble is constructed by maximizing an appropriately defined entropy subject to constraints, which is explicitly identified.
Time-Resolved Observation of Thermalization in an Isolated Quantum System.
TLDR
This work uses trapped atomic ions forming a hybrid Coulomb crystal and exploit its phonons to study an isolated quantum system composed of a single spin coupled to an engineered bosonic environment and observes the emergence of thermalization.
Quantum quench in an atomic one-dimensional Ising chain.
TLDR
This work reports significant modification of the tunneling rate induced by interactions and shows clear evidence for collective effects in the oscillatory response in an ensemble of tilted one-dimensional atomic Bose-Hubbard chains after a sudden quench.
Discrete Time Crystals in the Absence of Manifest Symmetries or Disorder in Open Quantum Systems.
TLDR
A semiclassical approach reveals the emergence of a robust discrete time-crystalline phase in the thermodynamic limit in which metastability, dissipation, and interparticle interactions play a crucial role.
Effective thermal dynamics following a quantum quench in a spin chain.
TLDR
The nonequilibrium dynamics of the quantum Ising model following an abrupt quench of the transverse field is studied, and it is observed that the dependence of tau(Q)(phi) on the effective temperature fairly agrees with that obtained in thermal equilibrium as a function of the equilibrium temperature.
Ballistic Spin Transport in a Periodically Driven Integrable Quantum System.
TLDR
An analytic family of quasilocal conservation laws that break the spin-reversal symmetry and compute a lower bound on the spin Drude weight, which is found to be a fractal function of the anisotropy parameter.
Quantum statistical mechanics in a closed system.
  • Deutsch
  • Physics, Medicine
    Physical review. A, Atomic, molecular, and optical physics
  • 1991
TLDR
A closed quantum-mechanical system with a large number of degrees of freedom does not necessarily give time averages in agreement with the microcanonical distribution, so by adding a finite but very small perturbation in the form of a random matrix, the results of quantum statistical mechanics are recovered.
Glimmers of a Quantum KAM Theorem: Insights from Quantum Quenches in One-Dimensional Bose Gases
Real-time dynamics in a quantum many-body system are inherently complicated and hence difficult to predict. There are, however, a special set of systems where these dynamics are theoretically
Signatures of integrability in the dynamics of Rydberg-blockaded chains
A recent experiment on a 51-atom Rydberg-blockaded chain observed anomalously long-lived temporal oscillations of local observables after quenching from an antiferromagnetic initial state. This
...
1
2
3
4
5
...