Entanglement and boundary entropy in quantum spin chains with arbitrary direction of the boundary magnetic fields

  title={Entanglement and boundary entropy in quantum spin chains with arbitrary direction of the boundary magnetic fields},
  author={J. C. Xavier and Morteza Rajabpour},
  journal={Physical Review B},
We calculate the entanglement and the universal boundary entropy (BE) in critical quantum spin chains, such as the transverse field Ising chain and the XXZ chain, with arbitrary direction of the boundary magnetic field (ADBMF). We determine the boundary universality class that an ADBMF induces. In particular, we show that the induced boundary conformal field theory depends on the point on the Bloch sphere where the boundary magnetic field directs. We show that the classification of the… 
1 Citations

Figures and Tables from this paper

Second R\'enyi entropy and annulus partition function for one-dimensional quantum critical systems with boundaries
We consider the entanglement entropy in critical one-dimensional quantum systems with open boundary conditions. We show that the second Rényi entropy of an interval away from the boundary can be


Quantum Entanglement
Entanglement is a fundamental resource in quantum information theory. It allows performing new kinds of communication, such as quantum teleportation and quantum dense coding. It is an essential
Entanglement spectrum degeneracy and the Cardy formula in 1+1 dimensional conformal field theories
We investigate the effect of a global degeneracy in the distribution of entanglement spectrum in conformal field theories in one spatial dimension. We relate the recently found universal expression
Exact boundary free energy of the open XXZ chain with arbitrary boundary conditions
We derive an exact formula for the boundary free energy of the open Heisenberg XXZ spin chain. We allow for arbitrary boundary magnetic fields, but assume zero bulk magnetization. The result is
Hydrodynamical phase transition for domain-wall melting in the XY chain
We study the melting of a domain wall, prepared as a certain low-energy excitation above the ferromagnetic ground state of the XY chain. In a well defined parameter regime the time-evolved
Universal Entropy of Conformal Critical Theories on a Klein Bottle.
  • Hong-Hao Tu
  • Mathematics, Medicine
    Physical review letters
  • 2017
We show that rational conformal field theories in 1+1 dimensions on a Klein bottle, with a length L and width β, satisfying L≫β, have a universal entropy. This universal entropy depends on the
Universal boundary entropies in conformal field theory: A quantum Monte Carlo study
Recently, entropy corrections on nonorientable manifolds such as the Klein bottle are proposed as a universal characterization of critical systems with an emergent conformal field theory (CFT). We
Entanglement entropy after selective measurements in quantum chains
A bstractWe study bipartite post measurement entanglement entropy after selective measurements in quantum chains. We first study the quantity for the critical systems that can be described by
Quantum thermalization through entanglement in an isolated many-body system
Microscopy of an evolving quantum system indicates that the full quantum state remains pure, whereas thermalization occurs on a local scale, whereas entanglement creates local entropy that validates the use of statistical physics for local observables.
Measuring entanglement entropy in a quantum many-body system
Making use of the single-site-resolved control of ultracold bosonic atoms in optical lattices, two identical copies of a many-body state are prepared and interfered to directly measure quantum purity, Rényi entanglement entropy, and mutual information.
Quantum Ising chains with boundary fields
We present a detailed study of the finite one-dimensional quantum Ising chain in a transverse field in the presence of boundary magnetic fields coupled with the order-parameter spin operator. We