Capacity of entanglement for scalar fields in squeezed states

TL;DR

This paper investigates the capacity of entanglement in squeezed scalar field states, revealing its volume law behavior at large squeezing and exploring its relation to other entanglement measures and potential holographic duals.

Contribution

It provides a detailed analysis of the capacity of entanglement in squeezed states, highlighting its universal dependence on squeezing and its connection to holography.

Findings

Capacity of entanglement obeys a volume law at large squeezing.

Capacity of entanglement's dependence on squeezing parameter is characterized.

Relations between capacity, entanglement, and Renyi entropies are discussed.

Abstract

We study various aspects of capacity of entanglement in the squeezed states of a scalar field theory. This quantity is a quantum informational counterpart of heat capacity and characterizes the width of the eigenvalue spectrum of the reduced density matrix. In particular, we carefully examine the dependence of capacity of entanglement and its universal terms on the squeezing parameter in the specific regimes of the parameter space. Remarkably, we find that the capacity of entanglement obeys a volume law in the large squeezing limit. We discuss how these results are consistent with the behavior of other entanglement measures including entanglement and Renyi entropies. We also comment on the existence of consistent holographic duals for a family of Gaussian states with generic squeezing parameter based on the ratio of entanglement entropy and the capacity of entanglement.