Stimulated quantum phase slips from weak electromagnetic radiations in superconducting nanowires

Amir Jafari-Salim,Mohammad H Ansari,A Hamed Majedi,Amin Eftekharian

doi:10.1063/1.4944482

Amir Jafari-Salim, Mohammad H Ansari + Show 2 more

Open Access

https://doi.org/10.1063/1.4944482

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Abstract

We study the rate of quantum phase slips in an ultranarrow superconducting nanowire exposed to weak electromagnetic radiations. The superconductor is in the dirty limit close to the superconducting-insulating transition, where fluxoids move in strong dissipation. We use a semiclassical approach and show that external radiation stimulates a significant enhancement in the probability of quantum phase slips.

Highlights

Quantum phase slip junctions are exact dual counterpart of the Josephson junctions
A difference between quantum phase slip (QPS) and thermally activated phase slips (TAPS) is that the dissipation in TAPS is due to stochastic energy activation in high temperature while QPS allows tunneling between distinct zero-current states
The approach chosen was to use the duality transformation between Josephson junction and a QPS junction to map the dynamics of QPS charge in a circuit model

Summary

INTRODUCTION

Quantum phase slip junctions are exact dual counterpart of the Josephson junctions. Recently these junctions have been successfully realized in ultranarrow superconducting nanowires, where quantum phase slip replaces tunneling Cooper pairs.[1,2] These nanowires are nonlinear elements performing similar physics as Josephson junctions with the roles of superconducting phase φ and charge q being interchanged.[3,4] This duality has been the motivation behind many of the recent applications of quantum phase slip (QPS) elements.[5,6,7,8] These elements have found interesting implications for fundamental metrology and information technology, for instance as photon pulse detectors, quantum current standard, and quantum bits.[7,8,9,10]. They enter an insulating state, and if condense, a coherent zero-resistance state emerges Based on this theory superconductor in SIT have regions of localized BCS-condensates nearly separated in different lakes.[16] The cores of QPS can coherently tunnel across superconducting regions and avoid dissipation. This is similar to the Cooper pairs that tunnel across a Josephson junction without much dissipation.[17,18]. We show that a fluxoid gains energy from radiation and tunnel into the barrier more often than usual and slips away This leads to the super-exponential enhancement in the rate of such ‘stimulated quantum phase slips’ (SQPs). This can result in larger DC resistivity with minimal fluctuations in a dynamical variable

STIMULATED QUANTUM PHASE SLIPS

CONCLUDING REMARKS