Tunable Supercurrent Through Semiconductor Nanowires
Yong-Joo Doh,1*
Jorden A. van Dam,1*
Aarnoud L. Roest,1,2
Erik P. A. M. Bakkers,2
Leo P. Kouwenhoven,1
Silvano De Franceschi1
Nanoscale superconductor/semiconductor hybrid devices are assembled
from indium arsenide semiconductor nanowires individually contacted
by aluminum-based superconductor electrodes. Below 1 kelvin,
the high transparency of the contacts gives rise to proximity-induced
superconductivity. The nanowires form superconducting weak links
operating as mesoscopic Josephson junctions with electrically
tunable coupling. The supercurrent can be switched on/off by
a gate voltage acting on the electron density in the nanowire.
A variation in gate voltage induces universal fluctuations in
the normal-state conductance, which are clearly correlated to
critical current fluctuations. The alternating-current Josephson
effect gives rise to Shapiro steps in the voltage-current characteristic
under microwave irradiation.
2 Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven, Netherlands.
* These authors contributed equally to this work
Present address: Laboratorio Nazionale TASC-INFM, I-34012 Trieste, Italy.
