Superfluid properties of dilute neutron matter

TL;DR

This paper presents non-perturbative AFQMC calculations of dilute neutron matter, revealing superfluid properties such as the energy gap and critical temperature, and indicating a non-BCS superfluid behavior at low temperatures.

Contribution

First non-perturbative AFQMC study of dilute neutron matter determining superfluid parameters and challenging BCS assumptions.

Findings

Energy gap at zero temperature is large.

Critical temperature is identified.

System exhibits non-BCS superfluid characteristics.

Abstract

We report results of fully non-perturbative calculations, based on Auxiliary Field Quantum Monte Carlo (AFQMC) approach, for the dilute neutron matter at the density $\rho=0.003\fm^{-3}$. Fundamental quantities which characterize the superfluid state: the single particle energy gap $\Delta(T)$, and the critical temperature $\Tc$ have been determined. The large value of $\Delta(0)/\Tc\approx 3.2$ indicates that the system is not a BCS-type superfluid at low temperatures.