Origin of excess low-energy states in a disordered superconductor in a Zeeman field
Tunneling density of states measurements of disordered superconducting 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 phase that occurs near the spin-paramagnetic transition at the Chandrasekhar-Clogston critical field. The disordered Larkin-Ovchinnikov superconductor is characterized by a pairing amplitude that changes sign at domain walls. These domain walls carry magnetization and support Andreev bound states that lead to distinct spectral signatures at low energy. © 2011 American Physical Society.
Publication Source (Journal or Book title)
Physical Review Letters
Loh, Y., Trivedi, N., Xiong, Y., Adams, P., & Catelani, G. (2011). Origin of excess low-energy states in a disordered superconductor in a Zeeman field. Physical Review Letters, 107 (6) https://doi.org/10.1103/PhysRevLett.107.067003