Effects of topological and non-topological edge states on information propagation and scrambling in a Floquet spin chain

• URL: http://arxiv.org/abs/2210.15302v2
• Date: Mon, 11 Dec 2023 10:46:21 GMT
• Title: Effects of topological and non-topological edge states on information propagation and scrambling in a Floquet spin chain
• Authors: Samudra Sur, Diptiman Sen
• Abstract summary: We numerically study the information propagation from one end of a periodically driven spin-1/2 $XY$ chain with open boundary conditions. For sinusoidal driving, the model can be shown to host different types of edge states.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The action of any local operator on a quantum system propagates through the system carrying the information of the operator. This is usually studied via the out-of-time-order correlator (OTOC). We numerically study the information propagation from one end of a periodically driven spin-1/2 $XY$ chain with open boundary conditions using the Floquet infinite-temperature OTOC. We calculate the OTOC for two different spin operators, $\sigma^x$ and $\sigma^z$. For sinusoidal driving, the model can be shown to host different types of edge states, namely, topological (Majorana) edge states and non-topological edge states. We observe a localization of information at the edge for both $\sigma^z$ and $\sigma^x$ OTOCs whenever edge states are present. In addition, in the case of non-topological edge states, we see oscillations of the OTOC in time near the edge, the oscillation period being inversely proportional to the gap between the Floquet eigenvalues of the edge states. We provide an analytical understanding of these effects due to the edge states. It was known earlier that the OTOC for the spin operator which is local in terms of Jordan-Wigner fermions ($\sigma^z$) shows no signature of information scrambling inside the light cone of propagation, while the OTOC for the spin operator which is non-local in terms of Jordan-Wigner fermions ($\sigma^x$) shows signatures of scrambling. We report a remarkable `unscrambling effect' in the $\sigma^x$ OTOC after reflections from the ends of the system. Finally, we demonstrate that the information propagates into the system mainly via the bulk states with the maximum value of the group velocity, and we show how this velocity is controlled by the driving frequency and amplitude.

Related papers

• Inverse participation ratio and entanglement of edge states in HgTe quantum wells in a finite strip geometry [0.0]
  Information on the edge states energies and wavefunctions is extracted from analytic and numerical Hamiltonian diagonalization approaches. Analysis of the structure of the edge-state wave functions in terms of spin, momentum $k_x$ in the $x$-direction and position $y$, evidences the spin polarization structure of edge states at the boundaries. The purity and entropies of the reduced density matrix (RDM) inform on the regions $(k_x,y)$ where the spin sector is more and less entangled with the rest of the system.
  arXiv  Detail & Related papers  (2024-07-17T10:46:19Z)
• KPZ scaling from the Krylov space [83.88591755871734]
  Recently, a superdiffusion exhibiting the Kardar-Parisi-Zhang scaling in late-time correlators and autocorrelators has been reported. Inspired by these results, we explore the KPZ scaling in correlation functions using their realization in the Krylov operator basis.
  arXiv  Detail & Related papers  (2024-06-04T20:57:59Z)
• Waveguide QED at the onset of spin-spin correlations [36.136619420474766]
  We find that molecules belonging to the crystal sublattice B form one-dimensional spin chains. The microwave transmission shows evidences for the collective coupling of quasi-identical spins to the propagating photons.
  arXiv  Detail & Related papers  (2024-04-04T18:00:05Z)
• Information-Theoretic Thresholds for Planted Dense Cycles [52.076657911275525]
  We study a random graph model for small-world networks which are ubiquitous in social and biological sciences. For both detection and recovery of the planted dense cycle, we characterize the information-theoretic thresholds in terms of $n$, $tau$, and an edge-wise signal-to-noise ratio $lambda$.
  arXiv  Detail & Related papers  (2024-02-01T03:39:01Z)
• Generation of complete graph states in a spin-$1/2$ Heisenberg chain with a globally optimized magnetic field [0.0]
  We introduce a method for generating multiparticle complete graph states using a spin$1/2$ Heisenberg $XX$ chain subjected to a time-varying magnetic field. Our scheme relies exclusively on nearest-neighbor interactions between atoms, with real-time magnetic field formation facilitated by quantum optimal control theory.
  arXiv  Detail & Related papers  (2024-01-03T21:32:35Z)
• Clustered Switchback Experiments: Near-Optimal Rates Under Spatiotemporal Interference [44.644520116360106]
  We estimate the global average treatment effect (GATE), the difference between average outcomes having exposed all units at all times to treatment or to control. We propose a clustered switchback design, where units are grouped into clusters and time steps are grouped into blocks. We show that for graphs that admit good clustering, a truncated exposure-mapping Horvitz-Thompson estimator achieves $tilde O(1/NT)$ mean-squared error (MSE), matching an $Omega (1/NT)$ lower bound up to logarithmic terms.
  arXiv  Detail & Related papers  (2023-12-25T01:00:58Z)
• Quantum-information theory of magnetic field influence on circular dots with different boundary conditions [0.0]
  2D circular quantum dots (QDs) whose circumference supports homogeneous either Dirichlet or Neumann boundary condition (BC) Physical interpretation is based on the different roles of the two BCs and their interplay with the field: Dirichlet (Neumann) surface is a repulsive (attractive) interface.
  arXiv  Detail & Related papers  (2023-06-28T11:33:11Z)
• Periodically driven Rydberg chains with staggered detuning [0.0]
  We study the stroboscopic dynamics of a driven finite Rydberg chain with staggered ($Delta$) and time-dependent uniform ($lambda(t)$) detuning terms using exact diagonalization (ED) We show that at intermediate drive ($omega_D$), the presence of a finite $Delta$ results in violation of the eigenstate thermalization hypothesis (ETH) via clustering of Floquet eigenstates. The violation of ETH in these driven finite-sized chains is also evident from the dynamical freezing displayed by the density density correlation function at specific $omega_D
  arXiv  Detail & Related papers  (2021-12-29T19:04:07Z)
• Information scrambling at finite temperature in local quantum systems [0.0]
  This paper investigates the temperature dependence of quantum information scrambling in local systems with an energy gap, $m$, above the ground state. We study the speed and shape of growing Heisenberg operators as quantified by out-of-time-order correlators.
  arXiv  Detail & Related papers  (2020-05-21T17:49:52Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)
• Anisotropy-mediated reentrant localization [62.997667081978825]
  We consider a 2d dipolar system, $d=2$, with the generalized dipole-dipole interaction $sim r-a$, and the power $a$ controlled experimentally in trapped-ion or Rydberg-atom systems. We show that the spatially homogeneous tilt $beta$ of the dipoles giving rise to the anisotropic dipole exchange leads to the non-trivial reentrant localization beyond the locator expansion.
  arXiv  Detail & Related papers  (2020-01-31T19:00:01Z)

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.