Superconducting Quantum Devices: SQUIDs, QuBits, and QuantumLimited Amplifiers
Introduction
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 reliablely fabricated using advanced thinfilm technologies and allow building macroscopic systems such as artificial atoms that show quantummechanical behaviour. The scalability, reproducibility and controllability of these systems facilitate to study complex quantummechanical 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 welldefined boundary conditions. Besides this, SQDs are used as the most sensitive devices for measuring or amplifying different physical quantities and are hotly tipped as very promising candidates for the implementation of a quantum computer.
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 quantum bits and give an introduction into quantum computing using SQDs. Finally, we deal with SQDbased quantumlimited amplifiers that are presently the only devices overcoming existing noise limits of conventional semiconductor electronics.
Content
 Introduction to superconductivity (perfect conductivity, ideal diagmagnetism, BCS theory, macroscopic wave function, magnetic flux quantization, Josephson effects)

Josephson tunnel junctions (realization of Josephson junctions, RCSJmodel, mechanical analogon, long and short Josephson junctions, behaviour in external magnetic fields, quantummechanical description of a Josephson junction)

Superconducting quantum interference devices (SQUIDs) (theoretical description of dc and rfSQUIDs, SQUID design, SQUID readout, SQUID applications)

SQUID based lowand highfrequency amplifiers

Microwave properties of superconductors, superconducting resonators

Superconducting Quantum Bits (Cooper pair box, flux qubit, phase qubit, transmon qubit, etc.)

Quantumlimited amplifiers, quantum measurements, quantummechanical description of amplifiers

Quantum computing, Deutsch and Shore algorithm, quantum error correction

Digital superconducting electronics
Prerequisite knowledge
Besides a general understanding of quantum mechanics, there is no prerequisite knowledge. All relevant aspects on superconductivity will be introduced within the lecture. Basic knowledge about solidstate physics as gained by the introduction into solidstate physics (PEP5) or the advanced lecture on condensed matter physics (CMP) are helpful.
Exam
Postexam review: February 20th, 2019, 14:0015:00 (KIP SR 2.404).
Please bring a student IDcard or photo ID. In case you want to review a colleague's exam you have to present a written authorization.
The exam will take place on February 6th, 2019, 14:0016:00 (Phil.Weg. 12 nHS).
Organization
 6 Credit points (6CPs) are available when passing the exam.
 Participation in the exam will be possible when reaching at least 50% of the available points of the problem sets.
 Registration for the plenary tutorial via webpage (mandatory!)
 10 points per problem set, 12 problem sets in total
Material
 Notes_Lecture_01.pdf
 Notes_Lecture_02.pdf
 Notes_Lecture_03.pdf
 Notes_Lecture_04.pdf
 Notes_Lecture_05.pdf
 Notes_Lecture_06.pdf
 Notes_Lecture_07.pdf
 Notes_Lecture_08.pdf
 Notes_Lecture_09.pdf
 Notes_Lecture_10.pdf
 Notes_Lecture_11.pdf
 Notes_Lecture_12.pdf
 Notes_Lecture_13.pdf
 Notes_Lecture_14.pdf
 Notes_Lecture_15.pdf
 Notes_Lecture_16.pdf
 Notes_Lecture_17.pdf
 Notes_Lecture_18.pdf
 Notes_Lecture_19.pdf
 Notes_Lecture_20.pdf
 Notes_Lecture_21.pdf
 Notes_Lecture_22.pdf
 Notes_Lecture_23.pdf
 Notes_Lecture_24.pdf
 Notes_Lecture_25.pdf
 Slides_General_Information.pdf
 Slides_Lecture_01.pdf
 Slides_Lecture_02.pdf
 Slides_Lecture_07.pdf
 Slides_Lecture_08.pdf
 Slides_Lecture_09.pdf
 Slides_Lecture_10.pdf
 Slides_Lecture_11.pdf
 Slides_Lecture_13.pdf
 Slides_Lecture_14.pdf
 Slides_Lecture_15.pdf
 Slides_Lecture_17.pdf
Exercise Sheets
 Übungsblatt 01
 Übungsblatt 02
 Übungsblatt 03
 Übungsblatt 04
 Übungsblatt 05
 Übungsblatt 06
 Übungsblatt 07
 Übungsblatt 08
 Übungsblatt 09
 Übungsblatt 10
 Übungsblatt 11
 Übungsblatt 12
Tutorials
 Gruppe 1 (Anna Ferring)
22 Teilnehmer/innen
INF 227 / SR 1.404, Mi 14:15  15:00