Static Response of Neutron Matter

TL;DR

This paper investigates the static response of neutron matter under periodic external modulation using Quantum Monte Carlo methods, providing insights relevant to neutron-star crusts and neutron-rich nuclei.

Contribution

It introduces a non-perturbative quantum Monte Carlo approach to study inhomogeneous neutron matter with periodic potentials, connecting microscopic calculations to energy-density functional theories.

Findings

Quantified the energy of neutron matter at various densities and external potential parameters.

Analyzed finite-size effects and wave function ansatz impacts on systematic errors.

Computed the static density-density linear response function of neutron matter.

Abstract

We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully non-perturbative microscopic Quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems.