3D-melting features of the irreversibility line in overdoped Bi$_2$Sr$_2$CuO$_6$ at ultra-low temperature and high magnetic field

TL;DR

This study investigates the vortex lattice melting behavior in overdoped Bi$_2$Sr$_2$CuO$_6$ at ultra-low temperatures and high magnetic fields, revealing a 3D-anisotropic melting line with implications for understanding vortex dynamics.

Contribution

It provides the first detailed measurement of the irreversibility line in overdoped Bi$_2$Sr$_2$CuO$_6$ at ultra-low temperatures and high fields, interpreting it as a 3D vortex lattice melting line.

Findings

Irreversibility line consistent with 3D anisotropic vortex melting

Lindemann number c_L=0.13 determined from data

Discussion of alternative melting models and magnetoresistance connection

Abstract

We have measured the irreversible magnetization of an overdoped Bi$_2$Sr$_2$CuO$_6$ single crystal up to B=28 T and down to T=60 mK, and extracted the irreversibility line $B_{\rm irr}(T)$: the data can be interpreted in the whole temperature range as a 3D-anisotropic vortex lattice melting line with Lindemann number $c_{\rm L}=0.13$. We also briefly discuss the applicability of alternative models such as 2D- and quantum melting, and the connection with magnetoresistance experiments.