Title :
Superconducting junctions using a 2DEG in a strained InAs quantum well inserted into an InAlAs/InGaAs MD structure
Author :
Akazaki, T. ; Nitta, J. ; Takayanagi, H. ; Arai, K.
Author_Institution :
NTT Basic Res. Labs., Atsugi, Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
A newly fabricated three-terminal Josephson junction is coupled with a two-dimensional electron gas (2DEG) in a strained InAs quantum well inserted into an InAlAs/InGaAs modulation-doped structure. The 2DEG is confined in the InAs quantum well and has a maximum mobility of 155000 cm/sup 2//Vs at a sheet-carrier density of 1.86/spl times/10/sup 12/ cm/sup -2/ at 10 K. The supercurrent flows through the 2DEG and can be controlled by adjusting the gate voltage. The critical current and normal resistance are measured as a function of the gate voltage, and the sheet-carrier density dependence of the critical current is obtained. We also measure the temperature dependence of the critical current at different gate voltages. The results indicate that, when using this junction, the superconducting characteristics can range between the clean and dirty limits.<>
Keywords :
Josephson effect; carrier density; critical current density (superconductivity); field effect transistors; semiconductor quantum wells; superconducting transistors; superconductor-semiconductor boundaries; two-dimensional electron gas; 10 K; 2DEG; InAlAs-InGaAs; JOFET; Nb; critical current; gate voltage; gate voltages; modulation-doped structure; normal resistance; semiconductor-coupled Josephson junctions; sheet-carrier density; strained quantum well; superconducting characteristics; three-terminal Josephson junction; two-dimensional electron gas; Critical current; Current measurement; Density measurement; Electrical resistance measurement; Electrons; Epitaxial layers; Indium compounds; Indium gallium arsenide; Josephson junctions; Voltage control;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
