MERA as a holographic strange correlator

TL;DR

This paper demonstrates how MERA tensor networks for 1D critical states can be viewed as strange correlators, revealing holographic features and a quantum corrected Ryu-Takayanagi formula through a dual 2D bulk state.

Contribution

It introduces a novel interpretation of MERA as a strange correlator, connecting 1D critical states to 2D holographic duals with emergent bulk features.

Findings

Bulk holographic features like horizon-like screens observed.

Quantum corrected Ryu-Takayanagi formula derived and tested.

Dual 2D bulk states exhibit gauge-like symmetries.

Abstract

The multi-scale entanglement renormalization ansatz (MERA) is a tensor network that can efficiently parameterize critical ground states on a 1D lattice, and also suggestively implement some aspects of the holographic correspondence of string theory on a lattice. Extending our recent work [S. Singh, Physical Review D 97, 026012 (2018); S. Singh, N. A. McMahon, and G. K. Brennen, Phys. Rev. D 97, 026013 (2018)], we show how the MERA representation of a 1D critical ground state---which has long range entanglement---can be viewed as a strange correlator: the overlap of a 2D state with short range entanglement and a 2D product state. Strange correlators were recently introduced to map 2D symmetry protected or topologically ordered quantum states to critical systems in one lower dimension. The 2D quantum state dual to the input 1D critical state is obtained by lifting the MERA, a procedure which introduces bulk quantum degrees of freedom by inserting intertwiner tensors on each bond of the MERA tensor network. We show how this dual 2D bulk state exhibits several features of holography, for example, appearance of horizon-like holographic screens and bulk gauging of global on-site symmetries at the boundary. We also derive a quantum corrected Ryu-Takayanagi formula relating boundary entanglement entropy to bulk geodesic lengths---as measured by bulk entropy---and numerically test it for ground states of a set of unitary minimal model CFTs, as realized by 1D anyonic Heisenberg models.