Upper critical field for electrons in two-dimensional lattice

TL;DR

This paper investigates the upper critical magnetic field in a two-dimensional lattice with on-site pairing, using a finite-system approach to analyze how magnetic fields affect superconductivity and quasiparticle states.

Contribution

It introduces a finite-system method to study magnetic and superconducting properties in a 2D lattice model, extending understanding of critical fields in such systems.

Findings

Quasiparticle density of states varies with magnetic field

Temperature dependence of the upper critical field is characterized

Potential extensions to high-temperature superconductor models

Abstract

We address a problem of the upper critical field in a lattice described by a two-dimensional tight-binding model with the on-site pairing. We develop a finite-system-approach which enables investigation of magnetic and superconducting properties of electrons on clusters, consisting of a few thousand sites. We discuss how the quasiparticle density of states changes with the applied external magnetic field and present the temperature dependence of the upper critical field. We also briefly discuss possible extension of the model to account for the properties of high-temperature superconductors.