Hysteresis in mesoscopic superconducting disks: the Bean-Livingston barrier

TL;DR

This paper explains hysteresis in mesoscopic superconducting disks using Ginzburg-Landau theory, highlighting the roles of surface and volume barriers and the impact of demagnetization effects on magnetization measurements.

Contribution

It provides a theoretical framework incorporating geometrical effects to explain hysteresis and anomalous magnetization signs in mesoscopic superconducting disks.

Findings

Hysteresis arises from surface barriers in large disks and volume barriers in small disks.

Demagnetization effects can cause measured magnetization to appear positive despite negative intrinsic magnetization.

Theoretical results align with experimental observations of magnetization behavior.

Abstract

The magnetization behavior of mesoscopic superconducting disks can show hysteretic behavior which we explain by using the Ginzburg-Landau (GL) theory and properly taking into account the de-magnetization effects due to geometrical form factors. In large disks the Bean-Livingston surface barrier is responsible for the hysteresis. While in small disks a volume barrier is responsible for this hysteresis. It is shown that although the sample magnetization is diamagnetic (negative), the measured magnetization can be positive at certain fields as observed experimentally, which is a consequence of the de-magnetization effects and the experimental set up.