Dresden 2017 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 69: Quantum Dots: Transport Properties I
HL 69.5: Talk
Thursday, March 23, 2017, 10:30–10:45, POT 151
Transmon qubits based on InAs/Al core/shell nanowire Josephson junctions — •Patrick Zellekens1,2, Steffen Schlör3, Arthur Leis1,2, Nicholas Güsken1,2, Torsten Rieger1,2, Mihail Ion Lepsa1,2, Alexander Pawlis1,2, Detlev Grützmacher1,2, Martin Weides3, and Thomas Schäpers1,2 — 1Peter Grünberg Institut 9, Forschungszentrum Jülich, Germany — 2JARA - Fundamentals of Future Information Technologies — 3Physikalisches Institut, Karlsruher Institut für Technologie
State-of-the-art qubits, like the Cooper pair box, are typically tuned in frequency by a magnetic field. Our goal is to fabricate an electrically tunable qubit, using a semiconductor nanowire Josephson junction as nonlinear element. If a gate voltage is applied to the nanowire, the charge carrier concentration is changed, which effectively leads to a change in the critical current and the kinetic inductance of the junction. Thereby it is possible to tune the resonance frequency of the qubit into the excitation frequency of the microwave cavity without a flux bias. The main limitation for the qubit performance is the semiconductor-superconductor interface. Here, the InAs nanowires grown by molecular beam epitaxy were in-situ covered by an Al shell. This procedure ensures a clean interface without any contamination. The electrical properties of the InAs nanowires was tuned by means of Te doping. Based on these InAs/Al core/shell nanowires Josephson junctions were fabricated. Subsequently, the junctions were electrically characterized at low temperature. Finally, implementations as building blocks for 3-dimensional transmon qubits will be shown.