String Theory and Quantum Spin Chains

TL;DR

This paper explores the connection between string theory and quantum spin chains by analyzing the Hamiltonian of large-N matrix models, revealing phase transitions and critical behavior in the groundstate as parameters vary.

Contribution

It introduces a novel interpretation of the space-time Hamiltonian as a quantum spin chain and studies its phase structure in the large-N limit.

Findings

Identification of parton and string phases in the groundstate

Discovery of a phase transition with non-trivial scaling

Groundstate energy diverges at the critical point

Abstract

The space-time light-cone Hamiltonian P^- of large-N matrix models for dynamical triangulations may be viewed as that of a quantum spin chain and analysed in a mean field approximation. As N -> infinity, the properties of the groundstate as a function of the bare worldsheet cosmological constant exhibit a parton phase and a critical string phase, separated by a transition with non-trivial scaling at which P- -> -infinity.