Onset of superconductivity in a voltage-biased normal-superconducting-normal microbridge

• Main Authors: Serbyn, Maksym (Contributor), Skvortsov, Mikhail A. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2014-08-18T14:36:10Z.
• Subjects: Article
• Online Access: Get fulltext

 We study the stability of the normal state in a mesoscopic NSN junction biased by a constant voltage V with respect to the formation of the superconducting order. Using the linearized time-dependent Ginzburg-Landau equation, we obtain the temperature dependence of the instability line, V[subscript inst] (T), where nucleation of superconductivity takes place. For sufficiently low biases, a stationary symmetric superconducting state emerges below the instability line. For higher biases, the normal phase is destroyed by the formation of a nonstationary bimodal state with two superconducting nuclei localized near the opposite terminals. The low-temperature and large-voltage behavior of the instability line is highly sensitive to the details of the inelastic relaxation mechanism in the wire. Therefore, experimental studies of V[subscript inst] (T) in NSN junctions may be used as an effective tool to access the parameters of the inelastic relaxation in the normal state.