Dislocations and vortices in pair density wave superconductors

TL;DR

This paper explores the properties of pair density wave superconductors, revealing their ability to induce spin density waves, support complex topological defects, and influence phase transitions in various physical systems.

Contribution

It demonstrates the existence of PDW states that induce SDW order and identifies novel topological defects combining dislocations and fractional vortices.

Findings

PDW states induce SDW order without magnetic field

Support for topological defects with combined dislocations and fractional vortices

Mechanism for fluctuation-driven non-superconducting phases

Abstract

With the ground breaking work of the Fulde, Ferell, Larkin, and Ovchinnikov (FFLO), it was realized that superconducting order can also break translational invariance; leading to a phase in which the Cooper pairs develop a coherent periodic spatially oscillating structure. Such pair density wave (PDW) superconductivity has become relevant in a diverse range of systems, including cuprates, organic superconductors, heavy fermion superconductors, cold atoms, and high density quark matter. Here we show that, in addition to charge density wave (CDW) order, there are PDW ground states that induce spin density wave (SDW) order when there is no applied magnetic field. Furthermore, we show that PDW phases support topological defects that combine dislocations in the induced CDW/SDW order with a fractional vortex in the usual superconducting order. These defects provide a mechanism for fluctuation driven non-superconducting CDW/SDW phases and conventional vortices with CDW/SDW order in the core.