Abstract
The superconducting state in one-dimensional nanosystems is very delicate. While fluctuations of the phase of the superconducting wave function lead to the spontaneous decay of persistent supercurrents in thin superconducting wires and nanocircuits, discrete phase-slip fluctuations can also lead to more exotic phenomena, such as the appearance of metastable superconducting states in current-bearing wires. Here we show that switching between different metastable superconducting states in δ-MoN nanowires can be very effectively manipulated by introducing small amplitude electrical noise. Furthermore, we show that deterministic switching between metastable superconducting states with different numbers of phase-slip centres can be achieved in both directions with small electrical current pulse perturbations of appropriate polarity. The observed current-controlled bi-stability is in remarkable agreement with theoretically predicted trajectories of the system switching between different limit cycle solutions of a model one-dimensional superconductor.
Highlights
The superconducting state in one-dimensional nanosystems is very delicate
Phase-slip process can be triggered below the critical current either classically by thermal fluctuations[20–22], or by quantum phase-slip (QPS) processes[23,24] at low temperatures
Such intrinsic phase-slip phenomena manifest themselves in two ways: (1) fluctuations induced phase-slip centre (PSC) lead to a finite resistivity of a superconducting wire, which depends on the number of PSCs3–13,19; and (2) current induced step-like current–voltage switching[5,14–16,25,26]
Summary
The superconducting state in one-dimensional nanosystems is very delicate. While fluctuations of the phase of the superconducting wave function lead to the spontaneous decay of persistent supercurrents in thin superconducting wires and nanocircuits, discrete phase-slip fluctuations can lead to more exotic phenomena, such as the appearance of metastable superconducting states in current-bearing wires. Investigations[3–19] of narrow superconducting channels revealed that very unusual dynamical resistance may appear in between the two states, whose properties are governed by spatial and temporal fluctuations of the phase y of the complex-order parameter c 1⁄4 jcjeiy Theory for such quasi-one-dimensional systems predicts a spatial variation of the order parameter of the form c 1⁄4 feikz where f 1⁄4 (1 À k2)1/2, and k depends on the current density via j 1⁄4 kð[1] À k2ÞcHc2x=f0 and z is distance along the wire measured in units of x. Phase-slip process can be triggered below the critical current either classically by thermal fluctuations[20–22], or by quantum phase-slip (QPS) processes[23,24] at low temperatures Such intrinsic phase-slip phenomena manifest themselves in two ways: (1) fluctuations induced PSCs lead to a finite resistivity of a superconducting wire, which depends on the number of PSCs3–13,19; and (2) current induced step-like current–voltage switching[5,14–16,25,26]. One can go to low temperatures, but specific heat and thermal conductivity both limit to zero as T-0, so heating is an ever-increasing problem at Voltage (V) Voltage (mV)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
