Anisotropic Superconductivity of Quasi-One-Dimensional Electrons in Magnetic Field

TL;DR

This paper theoretically investigates the transition temperature behavior of quasi-one-dimensional anisotropic superconductors, like organic conductors, under magnetic fields, highlighting differences between singlet and triplet pairing in various field regimes.

Contribution

It provides a theoretical analysis of how magnetic fields affect the transition temperature in anisotropic quasi-one-dimensional superconductors, emphasizing differences between singlet and triplet states.

Findings

Weak field: dH_c2/dT for singlet is  times larger than triplet.

Strong field: triplet transition temperature returns to zero-field value.

Singlet state is suppressed by Zeeman effect in strong magnetic fields.

Abstract

We study theoretically the transition temperature of a quasi-one-dimensional anisotropic superconductor in a magnetic field, which is thought to be realized in organic conductors,(TMTSF)2X. In the weak field limit,-dH_c2/dT for the anisotropic singlet is shown to be \sqrt{3} times larger than that for the anisotropic triplet in the case of attractive interaction of electrons at nearest-sites along c axis and magnetic field along the b axis. In the strong field region the transition temperature for spin-triplet is restored to zero field critical temperature while the anisotropic spin-singlet is suppressed by the Zeeman effect.