Scaling of entanglement entropy at deconfined quantum criticality

TL;DR

This paper introduces a novel nonequilibrium increment method to analyze entanglement entropy scaling at deconfined quantum critical points, revealing fundamental differences from conformal field theory predictions.

Contribution

The study develops a new computational method and uncovers unique entanglement entropy scaling behavior at DQC points, contrasting with known CFT results.

Findings

Universal area law with logarithmic corner corrections at conformal critical points

Negative corner correction exponent at DQC points

Fundamental differences between DQC and unitary CFT critical points

Abstract

We develop a nonequilibrium increment method to compute the R\'enyi entanglement entropy and investigate its scaling behavior at the deconfined critical (DQC) point via large-scale quantum Monte Carlo simulations. To benchmark the method, we first show that at an conformally-invariant critical point of O(3) transition, the entanglement entropy exhibits universal scaling behavior of area law with logarithmic corner corrections and the obtained correction exponent represents the current central charge of the critical theory. Then we move on to the deconfined quantum critical point, where although we still observe similar scaling behavior but with a very different exponent. Namely, the corner correction exponent is found to be negative. Such a negative exponent is in sharp contrast with positivity condition of the R\'enyi entanglement entropy, which holds for unitary conformal field theories(CFT). Our results unambiguously reveal fundamental differences between DQC and quantum critical points(QCPs) described by unitary CFTs.