Discussion Overview
The discussion revolves around deriving London's equation for superconductors, exploring theoretical foundations and interpretations. Participants reference various sources and concepts related to superconductivity, including canonical momentum, broken symmetry, and the response of superconductors to external fields.
Discussion Character
- Exploratory, Technical explanation, Conceptual clarification, Debate/contested
Main Points Raised
- One participant notes that the canonical momentum of the ground state of a superconductor is zero but questions the origin of this fact.
- Another participant suggests starting with the Wikipedia page on London equations, mentioning the minimal coupling prescription and the transformation of momentum.
- A different participant references broken symmetry arguments as a general explanation for the phenomenon, citing Weinberg's work.
- One participant expresses appreciation for a source provided but admits to a lack of understanding, requesting a simpler explanation without field theory.
- A later reply discusses Kittel's work on the response of superconductors to an applied transversal field, mentioning the concept of "rigidity of the wavefunction" and its implications for momentum expectation.
Areas of Agreement / Disagreement
Participants do not reach a consensus, as there are multiple competing views and approaches to understanding the derivation of London's equation.
Contextual Notes
Some claims depend on specific interpretations of theoretical concepts, and there are unresolved aspects regarding the application of broken symmetry and the implications of Kittel's findings.