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arXiv · 1111.6601

Unbalanced Holographic Superconductors and Spintronics

Francesco Bigazzi·Aldo L. Cotrone·Daniele Musso·Natalia Pinzani Fokeeva·Domenico Seminara
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Abstract

We present a minimal holographic model for s-wave superconductivity with unbalanced Fermi mixtures, in 2+1 dimensions at strong coupling. The breaking of a U(1)_A "charge" symmetry is driven by a non-trivial profile for a charged scalar field in a charged asymptotically AdS_4 black hole. The chemical potential imbalance is implemented by turning on the temporal component of a U(1)_B "spin" field under which the scalar field is uncharged. We study the phase diagram of the model and comment on the eventual (non) occurrence of LOFF-like inhomogeneous superconducting phases. Moreover, we study "charge" and "spin" transport, implementing a holographic realization (and a generalization thereof to superconducting setups) of Mott's two-current model which provides the theoretical basis of modern spintronics. Finally we comment on possible string or M-theory embeddings of our model and its higher dimensional generalizations, within consistent Kaluza-Klein truncations and brane-anti brane setups.

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Francesco Bigazzi, Aldo L. Cotrone, Daniele Musso, Natalia Pinzani Fokeeva, Domenico Seminara. 2011-11-28. Unbalanced Holographic Superconductors and Spintronics. https://doi.org/10.1007/jhep02(2012)078

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