Superconducting Quantum Devices: SQUIDs, Qubits, and Quantum-Limited Amplifiers

summer term 2016
Lecturer: Dr. Sebastian Kempf
Link to LSF
63 participants


Superconducting quantum devices (SQDs) are electrical circuits utilizing the unique features of superconductivity such as dissipationless direct current flow, ideal diamagnetism, magnetic flux quantization and Cooper pair tunneling. SQDs can nowadays be reliable fabricated using advanced thin-film technologies and allow building macroscopic systems such as artificial atoms that behave entirely quantum-mechanically. The scalability, reproducibility and controllability of these systems facilitate to study complex quantum mechanical systems while having the unique possibility to adjust key system parameters such as coupling strengths, operation frequencies or energy scales. SQDs are therefore an outstanding experimental playground for investigating new physics under well-defined boundary conditions. Besides this, SQDs are used as most sensitive devices for measuring or amplifying different physical quantities and are hotly tipped as very promising candidates for establishing quantum computers.
This lecture gives a comprehensive introduction into the physics and applications of superconducting quantum devices. In particular, we discuss the physics of Josephson tunneling junctions which are of similar importance for SQDs than transistors for modern semiconductor circuits. We cover superconducting quantum interference devices (SQUIDs) that are presently the most sensitive wideband devices for measuring various physical quantities such as voltage, current or magnetic field that can be naturally converted into magnetic flux. We discuss different kinds of superconducting Qubits and give an introduction into quantum computing using SQDs. Finally, we deal with SQD-based quantum-limited amplifiers that are presently the only devices overcoming existing noise limits of conventional semiconductor electronics.


  • Introduction to superconductivity
  • Josephson tunnel junctions
  • Superconducting quantum interference devices (SQUIDs)
  • SQUID based low-and high-frequency amplifiers
  • Microwave properties of superconductors, superconducting resonators
  • Qubits
  • Quantum-limited amplifiers, quantum measurements, QM description of amplifiers
  • Quantum computing
  • Digital superconducting electronics

Prerequisite knowledge

There is no prerequisite knowledge. All relevant aspects on superconductivity will be introduced briefly. However, basic knowledge about solid-state physics as imparted by the introduction into solid-state physics (PEP5) or the advanced lecture on condensed matter physics (CMP) might be helpful.

Supporting material, literature

There are many textbooks dealing with superconducting quantum devices. The following lists gives some books that are used for preparing the lecture:

  • C. Enss, S. Hunklinger: Low Temperature Physics
  • R. Gross, A. Marx: Festkörperphysik
  • M. Tinkham: Introduction to superconductivity
  • J. Clarke, A.I. Braginski (eds.): The SQUID Handbook - Fundamentals and Technology of SQUIDs and SQUID Systems
  • P. Seidel (ed.): Applied Superconductivity - Handbook on Devices and Applications
  • K. Likharev: Dynamics of Josephson Junctions and Circuits
  • A. Barone, G. Paterno: Physics and Applications of the Josephson Effect
  • R. Gross, A. Marx: Applied Superconductivity (lecture notes)
In the lecture, additional reviews on several topics will be cited.


There will be no tutorials. Credit points (2CPs) will be assigned due to attendance in the lecture which will be proved by signing an attendance list every week. For creating this list, registration in the excercise group 'Gruppe 1' will be greatly acknowledged.

Practice groups

Superconducting Quantum Devices: SQUIDs, QuBits, and Quantum-Limited Amplifiers
summer term 2016
Link zum LSF
63 participants