Synchronization of high-frequency oscillations of phase-slip centers in a tin whisker under microwave radiation

TL;DR

This study experimentally investigates how phase-slip centers in a tin whisker synchronize their high-frequency oscillations under microwave radiation, revealing quantized steps in voltage and the potential for microwave power generation.

Contribution

It demonstrates the synchronization of phase-slip center oscillations with external microwave fields and identifies conditions for quantized voltage steps in a tin whisker.

Findings

Observation of zero-slope steps at quantized voltages U_{m/n}

Detection of nonharmonic microwave radiation from phase-slip centers

Estimated microwave power output of 10^{-8} W

Abstract

Current-voltage characteristics of a system with a variable number of phase-slip centers resulting from phase separation in a tin whisker under external microwave field with a frequency \Omega/2\pi\=35-45 GHz have been studied experimentally. Emergence and disappearance of steps with zero slope in a whisker's current-voltage characteristic at U_{m/n}=(m/n)U_{\Omega}, where m and n are integers and U_{\Omega} is determined by Josephson's formula \hbar\Omega=2eU_{\Omega}, have been investigated. Microwave field generated by phase-slip centers is nonharmonic, and the system of phase-slip centers permits synchronization of internal oscillations at a microwave frequency by an external field with a frequency which is the n-th harmonic of internal oscillations. The estimated microwave power generated by a whisker is 10^{-8} W. Stimulation of superconductivity in a current-carrying whisker has been detected.