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arXiv · 1102.3889

Mystery of Excess Low Energy States in a Disordered Superconductor in a Zeeman Field

Y. L. Loh·N. Trivedi·Y. M. Xiong·P. W. Adams·G. Catelani
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Abstract

Tunneling density of states measurements of disordered superconducting (SC) Al films in high Zeeman fields reveal a significant population of subgap states which cannot be explained by standard BCS theory. We provide a natural explanation of these excess states in terms of a novel disordered Larkin-Ovchinnikov (dLO) phase that occurs near the spin-paramagnetic transition at the Chandrasekhar-Clogston critical field. The dLO superconductor is characterized by a pairing amplitude that changes sign at domain walls. These domain walls carry magnetization and support Andreev bound states, which lead to distinct spectral signatures at low energy.

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Y. L. Loh, N. Trivedi, Y. M. Xiong, P. W. Adams, G. Catelani. 2011-08-21. Mystery of Excess Low Energy States in a Disordered Superconductor in a Zeeman Field. https://doi.org/10.1103/physrevlett.107.067003

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