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Quasiparticle Density of States Measurements in Clean Superconducting AlMn Alloys



Galen C. O'Neil, Daniel R. Schmidt, Nathan A. Tomlin, Joel N. Ullom


Aluminum doped with Manganese (AlMn) forms a superconducting alloy with the transition temperature suppressed by the added Manganese. We present quasiparticle density of states measurements on superconducting AlMn alloys made by current-voltage measurements on normalmetal/ insulator/supercondutor tunnel junctions. The density of states remains BCS-like with a reduced gap, matching the predictions of Kaiser. However we measure additional subgap states not predicted by Kaiser, and demonstrate that these subgap states will harm some potential applications.
Physical Review B


Microrefrigerator, Normal-insulator-superconductor tunnel junction, Implanted superconductor, Superconducting density of states


O'Neil, G. , Schmidt, D. , Tomlin, N. and Ullom, J. (2010), Quasiparticle Density of States Measurements in Clean Superconducting AlMn Alloys, Physical Review B, [online], (Accessed April 14, 2024)
Created May 6, 2010, Updated February 19, 2017