Improved treatment of blocking effect at finite temperature

TL;DR

This paper investigates how the blocking effect influences pairing properties in odd-fermion systems at finite temperature, comparing various approximations with exact solutions to identify the most accurate approach.

Contribution

It introduces an improved approximation for the blocking effect at finite temperature, favoring the occupation of the top level near the Fermi surface.

Findings

The approximation with the odd particle on the top level aligns best with exact solutions.

Occupation number of the top level decreases as temperature increases.

The study enhances understanding of pairing interactions in odd-fermion systems at finite temperature.

Abstract

The blocking effect caused by the odd particle on the pairing properties of systems with odd number of fermions at finite temperature interacting via the monopole pairing force is studied within several approximations. The results are compared with the predictions obtained by using the exact solutions of the pairing Hamiltonian. The comparison favors the approximation with the odd particle occupying the top level, which is the closest to the Fermi surface and whose occupation number decreases with increasing temperature.