Scaling of Entanglement Entropy at Deconfined Quantum Criticality

We develop a nonequilibrium increment method to compute the Renyi 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 a 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 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 the positivity condition of the Renyi entanglement entropy, which holds for unitary conformal field theories (CFTs). Our results unambiguously reveal fundamental differences between DQC and quantum critical points described by unitary CFTs.

Automated summary

We develop a nonequilibrium increment method to calculate the Renyi entanglement entropy and study its scaling behavior at the deconfined critical point through large-scale quantum Monte Carlo simulations. Our results reveal fundamental differences between deconfined quantum critical points and quantum critical points described by unitary conformal field theories, as the corner correction exponent in the former case is found to be negative, in contrast to the positivity condition of the Renyi entanglement entropy.