Entanglement and particle production from cosmological perturbations: a quantum optical simulation approach

TL;DR

This paper introduces a quantum optical simulation framework using Gaussian formalism to study entanglement and particle production during cosmological inflation, validated against analytical bounds and extended to noisy environments.

Contribution

It develops an efficient computational approach combining Gaussian formalism and symplectic circuits to simulate cosmological perturbations and entanglement dynamics.

Findings

Validated simulation results with analytical entropy bounds.

Demonstrated the impact of thermal noise on entanglement measures.

Showed the framework's applicability across different cosmological backgrounds.

Abstract

In this work, we develop a computational framework based on the Gaussian formalism and symplectic circuit representation to explore cosmological perturbations during inflation. These tools offer an efficient means to study entanglement generation and particle production, particularly when analytical methods become insufficient and numerical simulations are essential. By evolving an initial Bunch-Davies vacuum through a two-mode squeezer, we simulate the behavior of the von Neumann entropy and logarithmic negativity across a wide range of cosmological backgrounds, each characterized by a distinct equation of state. The von Neumann entropy obtained via QuGIT simulations is compared with analytic R\'enyi entropy bounds, thereby validating the accuracy of our circuit implementation of the cosmological squeezing Hamiltonian in both accelerating and decelerating scenarios. We further investigate the role of thermal noise and demonstrate how the von Neumann entropy and logarithmic negativity are affected by its presence.