Entanglement and fluctuations in the Majumdar-Ghosh model ground state

Authors

Jade Farrah Dianne Mendoza; Francis N. C. Paraan

Source

Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress, Brisbane, Australia, QUICC S1 (2016).

Abstract

The matrix product state representation of the ground state of the Majumdar–Ghosh Model (MGM) is used to obtain the reduced density matrix of a block of x spins in a periodic MGM chain. This calculation leads to exact expressions for the entanglement entropy and subsystem fluctuations as a function of block length. We find that the entanglement entropy saturates exponentially to ln 3, even as the subsystem Hilbert space is five-dimensional.