Physics and Applications of Superconductivity

Sommersemester 2019
Dozent: PD Dr. Sebastian Kempf
Link zum LSF
25 Teilnehmer/innen

Introduction

Superconductivity, i.e. the effect of zero electrical dc resistance as well as the expulsion of magnetic fields (perfect diamagnetism) of certain materials below a characteristic critical temperature, is one of the most fascinating and astonishing effects in solid state physics. It plays technologically an important role in many modern scientific, medical and industrial applications and establishes, for example, the basis for realizing high field electromagnets to be used in magnetic resonance imaging (MRI) systems in healthcare or for guiding charged particle in modern particle accelerators such as the LHC. Moreover, it allows to build not only sensing devices such as magnetic field sensors or energy-dispersive single particle detectors exceeding the performance of conventional devices by orders of magnitude but also artifical atoms to study macroscopic quantum-mechanical systems while having the unique possibilty to adjust key system parameters such as energy levels or coupling strengths or building blocks for quantum information processing applications. In addition, it is conceivable that superconductivity will be utilized in near future for energy and traffic engineering applications, e.g. for dissipationless power transmission over large distances or high-speed trains connecting major cities.

Content

The lecture will give a comprehensive introduction into the physics and applications of superconductivity. In particular, it will cover the following topics:

Historical remarks
Reminder about normal metals: free electron gas, Drude and Sommerfeld model, electrical and thermal properties, band structure
Phenomena of superconductivity: zero electrical dc resistance and expulsion of magnetic fields (ideal diamagnetism, Meissner-Ochsenfeld effect)
Thermodynamics and thermal properties of superconductors
Phenomenological theories of superconductivity: Two-fluid model, London theory, Pippard theory, Ginzburg-Landau (GL) theory,
Microscropic theory of conventional superconductors: Bardeen-Cooper-Schrieffer (BCS) theory
Type I and type II superconductivity
Magnetic properties of type I and type II superconductors, the intermediate state, vortices, flux motion
Irreversible magnetic properties
Energy gap and quasiparticle tunneling (NIN, SIN, SIS tunnel junctions)
Conventional (classical) and unconventional (cuprate, non-cuprate, iron-based) superconductors
High-frequency electrodynamics of superconductors
Macroscopic quantum effects: Magnetic flux quantization and Josephson effects,
Josephson tunnel junctions, Josephson voltage standard, superconducting quantum interference devices (SQUIDs), superconducting quantum bits, SIS mixers and detectors
Modern calorimetric and bolometric detectors: Superconducting tunnel junctions (STJs), transition-edge sensors (TESs), microwave kinetic inductance detectors (MKIDs)
Superconducting coils and magnets

Prerequisite knowledge

Besides a general understanding of quantum mechanics and solid state physics as gained by attending the introduction into solid state physics (PEP5) or the advanced lecture on condensed matter physics (CMP), there is no prerequisite knowledge. A general reminder about the most important aspects of solid state physics which is required to understand the phenomomen of superconductivity will be given in the beginning of the lecture.

Exam

The exam will take place on August 6th, 2019, 10:00-12:00 (KIP HS 2). More details will be announced later.

Post-exam review: August 13th, 2019, 13:00-14:00 (KIP SR 2.402).

Organization

8 credit points will be available when passing the exam.
Participation in the exam is possible when reaching at least 50% of the available points of the problem sets.
Each week a problem set is handed out. The students have one week to find a solution / think about the problems. In the tutorial, the students indicate that they are prepared and in general willing to present their solution at the blackboard. For each indication ('cross') one point is attributed.
Registration for the tutorial (2 SWS) mandatory via webpage.

Literature

The lecture is based on the following excellent textbooks about superconductivity:

M. Tinkham, Introduction into superconductivity, Dover Publications
R. Kleiner, W. Buckel, Superconductivity - An Introduction, Wiley-VCH
C.H. Poole Jr., R. Prozorov, H.A. Farach, R.J. Creswick, Superconductivity, Elsevier Insights
P. Mangin, R. Kahn, Superconductivity - An introduction, Springer
P.G. de Gennes, Superconductivity of Metals and Alloys, Perseus Books

In addition, several original publications and review article will be cited. Furthermore, the following textbooks (incomplete list) covering different aspects of solid state physics and low-temperature physics might be helpful:

C. Enss, S. Hunklinger, Low-temperature Physics, Springer
S. Hunklinger, Festkörperphysik, Oldenburg Verlag
R. Gross, A. Marx, Festkörperphysik, de Gruyter Verlag
N. W. Ashcroft, N. Mermin, Solid State Physics,
C. Kittel, Introduction to Solid State Physics, Wiley

Material

Übungsblätter

Practice groups

Gruppe 1 (A. Reifenberger)
14 Teilnehmer/innen
INF 227 / SR 3.403, We 16:15 - 18:00
Gruppe 2 (M. Wegner)
11 Teilnehmer/innen
INF 227 / SR 3.404, We 16:15 - 18:00