Freiburg 2019 – wissenschaftliches Programm

Sitzungen | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

FM: Fall Meeting

FM 59: Enabling Technologies: Quantum Dots and Superconductivity-based Systems

FM 59.5: Talk

Mittwoch, 25. September 2019, 15:00–15:15, 3043

Towards semiconductor-superconductor hybrid qubits based on core/shell nanowires — •Patrick Zellekens^1,2, Russell Deacon^3,4, Pujitha Perla^1,2, Steffen Schlör⁵, Mihail Ion Lepsa^1,2, Martin Weides⁵, Koji Ishibashi^3,4, Detlev Grützmacher^1,2, and Thomas Schäpers^1,2 — ¹Peter Grünberg Institute, Forschungszentrum Jülich, 52428 Jülich, Germany — ²JARA-FIT, Fundamentals of Future Information Technology — ³RIKEN Center for Emergent Matter Science, 351-0198 Saitama, Japan — ⁴Advanced Device Laboratory, RIKEN, 351-0198 Saitama, Japan — ⁵Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany

State-of-the-art qubits are typically tuned in frequency by a magnetic field. Our goal is to fabricate and characterize electrically tunable qubits, i.e. Gatemon and Andreev qubits, using a semiconductor nanowire Josephson junction as nonlinear element.

The main limitation for the qubit performance is the semiconductor-superconductor interface. We present a detailed analysis of the DC- and AC-properties of InAs/Al and InAs/Nb nanowire Josephson junctions with epitaxially grown superconductor shells based on Shapiro, emission and gate-dependent VI measurements.

Additionally, we present flux- and gate-dependent measurements of Andreev qubits as well as the spectroscopy of individual Andreev bound states by means of pump-probe experiments. The latter one reveals a Rashba- induced lifting of the spin degeneracy, which is one of the prerequisites for the realization of Majorana fermions.