Entanglement Entropy, Quantum Fluctuations, and Thermal Entropy in Topological Phases

Understand

Entanglement entropy in topologically ordered matter phases has been computed extensively using various methods.

• In this paper, we study the entanglement entropy of topological phases in two-spaces from a new perspective---the perspective of quasiparticle fluctuations.
• In this picture, the entanglement spectrum of a topologically ordered system is identified with the spectrum of quasiparticle fluctuations of the system, and the entanglement entropy measures the maximal quasiparticle fluctuations on the EB.
• As a consequence, entanglement entropy corresponds to the thermal entropy of the quasiparticles at infinite temperature on the entanglement boundary.