Field-induced collective spin-exciton condensation in a quasi-2D dx2-y2-wave heavy electron superconductor

TL;DR

This paper explores how a magnetic field induces a collective spin-exciton condensation in a quasi-2D heavy electron superconductor, leading to a coexistence of superconductivity and spin density wave order, explaining high-field phases.

Contribution

It proposes a theoretical framework linking spin-exciton modes to field-induced phase transitions in CeCoIn5, advancing understanding of its high-field low-temperature behavior.

Findings

Identification of a collective spin-exciton mode in CeCoIn5

Proposal of a field-induced coexistence of superconductivity and SDW order

Explanation of the high-field-low-temperature phase in CeCoIn5

Abstract

The origin of the spin resonance observed in CeCoIn5 with Inelastic Neutron Scattering is subject to debate. It has been shown recently that in this heavy electron compound at low temperature an instability to a ground state with coexisting dx2 -y2 -wave superconductivity and Spin Density Wave (SDW) order in a magnetic field is a corollary of the consideration of a collective spin excitation mode in a quasi-2D dx2 -y2 -wave Pauli-limited superconductor. This provides a natural scenario for the occurence of the puzzling high-field-low-temperature phase highlighted in CeCoIn5 . We present perspectives on this ground state transition and propose directions for future experiment.