Spontaneous vortex dynamics in superconducting FeTe thin films

Abstract Superconductivity is realized in Fe 1+ x Te ( x =0.1–0.2) thin films grown on topological insulator Bi 2 Te 3 by molecular beam epitaxy. A thorough analysis of the obtained transport data in terms of the vortex glass theory reveals the occurrence of a spontaneous vortex glass phase transition in the superconducting Fe 1+ x Te films. Such a phase transition is ascribed to the presence of excess Fe in Fe 1+ x Te, indicating the important role of excess Fe in the vortex dynamics of iron chalcogenide. Based on the transport data, a phase diagram of Fe 1+ x Te is also constructed.