Yuki Nojiri

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Herstellung von verlustarmen Josephson-Kontakten für Quanten-Bauelemente

Josephson junctions (JJs) represent a fundamental building block of modern quantum circuits such as superconducting qubits or Josephson parametric amplifiers. The JJs are conventionally fabricated with Al while the surrounding quantum circuits are often made of Nb. Henceforth, there is a need of galvanic connection between them which includes removing Nb oxide via ion milling.  As a consequence, one needs to develop a careful milling and fabrication technique in order to preserve a low-loss microwave environment in the close vicinity of JJs. This task is of paramount importance for achieving high coherence times of the related quantum devices.

The goal of this Master project is to develop a fabrication technique for Al/Nb superconducting circuits which will include Ar/O2 milling. This also includes cryogenic microwave studies of fabricated superconducting circuits (such as Josephson parametric amplifiers and transmon qubits) and participation in experiments towards quantum information processing with superconducting devices.

suitable as

• Bachelor’s Thesis Physics
• Master’s Thesis Condensed Matter Physics
• Master’s Thesis Applied and Engineering Physics
• Master’s Thesis Quantum Science & Technology

Supervisor: Frank Deppe