Anomalous Peak Effect in CeRu2 and NbSe2 : Fracturing of a Flux Line Lattice?

TL;DR

This paper investigates the Peak Effect in CeRu2 and NbSe2, proposing that a disorder-induced fracturing transition of the flux line lattice explains the observed magnetic anomalies, challenging previous theories of order parameter modulation.

Contribution

It introduces the concept of a fracturing transition of the flux line lattice as an explanation for the Peak Effect, contrasting with prior theories involving order parameter modulation.

Findings

Discontinuous screening response near PE onset

History dependence in magnetic response

Evidence supporting fracturing of flux line lattice

Abstract

CeRu2 and 2H-NbSe2 display remarkable similarities in their magnetic response, reflecting the manner in which the weakly pinned flux line lattice (FLL) loses spatial order in the Peak Effect (PE) regime. The discontinuous change in screening response near the onset of PE and the history dependence in it are attributed to a disorder-induced fracturing transition of the FLL, as an alternative to the scenario involving the appearance of a spatial modulation in superconducting order parameter in CeRu2.