Current-Phase Relationship, Thermal and Quantum Phase Slips in Superconducting Nanowires Made on a Scaffold Created Using Adhesive Tape

Abstract

Quantum phase slippage (QPS) in a superconducting nanowire is a new candidate for developing a quantum bit [ 1 , 2 ]. It has also been theoretically predicted that the occurrence of QPS significantly changes the current-phase relationship (CPR) of the wire due to the tunneling between topologically different metastable states [ 3 ]. We present studies on the microwave response of the superconducting nanowires to reveal their CPRs. First, we demonstrate a simple nanowire fabrication technique, based on commercially available adhesive tapes, which allows making thin superconducting wire from different metals. We compare the resistance vs. temperature curves of Mo 76 Ge 24 and Al nanowires to the classical and quantum models of phase slips. In order to describe the experimentally observed microwave responses of these nanowires, we use the McCumber-Stewart model [ 4 ], which is generalized to include either classical or quantum CPR.

Superconducting nanowire quantum interference device based on Nb ultrathin films deposited on self-assembled porous Si templates

“…However, the value of the activation energy extracted here, U (0) = 3.9 meV, does not differ much from the value estimated in Ref. [52], while it is quite different from the one derived from the theoretical expression [58]. This discrepancy, as the similar one reported in Ref.…”

Microwave Response of SuperconductingYBa2Cu3O7−δNanowire Bridges Sustaining the Critical Depairing Current: Evidence of Josephson-li

“…5(b), where the Shapiro-like steps appear as dark blue regions. The periodic modulation of the current steps with the applied microwave amplitude gives a strong indication of the existence of an effective periodic current phase relation in the nanobridges [40]. The observation of up to 160 Shapiro steps, shown in Fig 5(c), further corroborates the excellent quality of our bridges since any inhomogeneity in the superconducting properties would inhibit the coherent motion of Abrikosov vortices and consequently the Josephson-like behavior [17].…”

Giant fractional Shapiro steps in anisotropic Josephson junction arrays

“…To investigate the harmonic content of the current-phase relationship in these novel weak link materials, experiments relying on detecting the phase-locked response of a current driven Josephson junction when subjected to a high frequency radiation field of frequency, ν rf , have recently been used [10][11][12][13][14][15] . In case the weak link is characterized by a conventional sinusoidal current-phase relationship, this resonant response manifests itself as constant voltage plateaus, so called Shapiro steps, in the voltage versus current (VI)-characteristics of the junction at voltages V n = nΦ 0 ν rf , where n 2 Z and Φ 0 the fluxquantum 16 .…”