Aspects of capacity of entanglement

Understand

Many quantum information theoretic quantities are similar to and/or inspired by thermodynamic quantities, with entanglement entropy being a well-known example.

• In this paper, we study a less well-known example, capacity of entanglement, which is the quantum information theoretic counterpart of heat capacity.
• It can be defined as the second cumulant of the entanglement spectrum and can be loosely thought of as the variance in the entanglement entropy.
• We review the definition of capacity of entanglement and its relation to various other quantities such as fidelity susceptibility and Fisher information.