Strength of the Vortex-Pinning Interaction from Real-Time Dynamics

TL;DR

This paper introduces a real-time dynamic method to accurately compute vortex-pinning interactions in various physical systems, overcoming previous uncertainties related to matter redistribution and ensemble choices.

Contribution

The authors develop a general, efficient real-time dynamic approach to determine vortex-pinning interactions at any separation, validated with Gross-Pitaevskii-like equations and applicable to neutron star crusts.

Findings

Validated method with Gross-Pitaevskii-like equations

Demonstrated application to neutron star crusts

Overcame uncertainties in previous approaches

Abstract

We present an efficient and general method to compute vortex-pinning interactions - which arise in neutron stars, superconductors, and trapped cold atoms - at arbitrary separations using real-time dynamics. This method overcomes uncertainties associated with matter redistribution by the vortex position and the related choice of ensemble that plague the typical approach of comparing energy differences between stationary pinned and unpinned configurations: uncertainties that prevent agreement in the literature on the sign and magnitude of the vortex-nucleus interaction in the crust of neutron stars. We demonstrate and validate the method with Gross-Pitaevskii-like equations for the unitary Fermi gas, and demonstrate how the technique of adiabatic state preparation with time-dependent simulation can be used to calculate vortex-pinning interactions in fermionic systems such as the vortex-nucleus interaction in the crust of neutron stars.