Physics - 39 Fall 2025

Physics 139/239 -- Fall 2025 -- University of California San Diego, Department of Physics

Instructor: Jorge E. Hirsch

Kammerlingh Onnes Walther Meissner Fritz London John Bardeen Hannes Alfvén

Understanding the Meissner Effect in Superconductors

The Meissner effect is the expulsion of a magnetic field from the interior of a metal entering the superconducting state. It was discovered experimentally 90 years ago and is the most fundamental property of superconductors. It is generally believed to be well understood both macroscopically and microscopically through London’s equations (1935) and BCS theory (1957). In this course we will discuss what is wrong with the general understanding of the Meissner effect and how to understand it correctly. This leads to qualitatively different guidelines from those being used today to guide the search for materials that will superconduct at room temperature.

Announcements

Read the Meissner-Ochsenfeld paper in English here
Read the Meissner-Ochsenfeld paper in its original German here
Slides and podcasts of lectures will be in Canvas page

Broad outline of topics that will be covered

Basic properties of superconductors, especially the Meissner effect
What the conventional theory of superconductivity explains and doesn't explain about the Meissner effect
The four questions about the Meissner effect that need to be answered
Alfven's theorem and the Meissner effect
Superconductors as giant atoms
Why the Meissner effect is an unknown unknown; experiments that could settle these questions
How the correct understanding of the Meissner effect tells us where to look for room temperature superconductors
How room temperature superconductors will change the world
Topics that will be covered, in more detail

Course Information:

Lectures: Tu Th 11:00am - 12:20p, YORK 3000A

Final: Wed Dec 10, 11:30am - 2:29p, YORK 3000A

Instructor: Jorge E. Hirsch, 5310 Mayer Hall, Ext. 4-3931, e-mail: jhirsch@ucsd.edu (include 139 in subject line)
In addition, we may have some distinguished guest lecturers presenting dissenting viewpoints

Office Hours: Mon 2-3pm, Fri 2-3pm, or by appointment, in person at 5310 MH or by zoom. For zoom click here.

Course Materials:

Books and other references
Canvas webpage
Web links

Course requirements:

All students: review what you learned in earlier courses about Newton's laws, Faraday's law, Ampere's law, the Bohr atom and the first and second laws of thermodynamics.
239 students: in addition, review what you learned in earlier courses about quantum mechanics, statistical physics, solid state physics and BCS theory
Other requirements to earn an A in the course will be discussed at the first lecture, thereafter be listed here

General Information