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arXiv · 1411.5882

Spontaneous appearance of nonzero momentum Cooper pairing: Possible application to the iron-pnictides

Michał Zegrodnik·Jozef Spałek
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Abstract

We suggest that an inhomogeneous (non-zero momentum) paired phase can appear in the absence of an external magnetic field in the system with a predominant interband pairing and with separate Fermi-surface sheets. The Fermi wave vector mismatch which appears in such situation can be compensated by nonzero center-of-mass momentum of the Cooper pairs, what can lead to a spontaneous appearance of the Fulde-Ferrell type of superconducting state. The idea is examined using a tight-binding model which emulates the hole-like and the electron-like bands of iron based superconductor. The state can appear for the case of both spin-singlet and -triplet pairing channels.

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Michał Zegrodnik, Jozef Spałek. 2014-11-21. Spontaneous appearance of nonzero momentum Cooper pairing: Possible application to the iron-pnictides. https://doi.org/10.1103/physrevb.90.174507

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