All Questions
Tagged with collective-excitations symmetry-breaking
2
questions
3
votes
0
answers
196
views
Goldstone Modes, Galilean Symmetry, and Negative Excitations in Fermi Gas
Considering the centrality of Goldstone quasiparticles in condensed matter theories, I was wondering if the converse of the theorem might also be true: Does the existence of a gapless excitation imply ...
- 1,350
7
votes
4
answers
810
views
Why does the breaking of a 'continuous' symmetry lead to gapless excitations but not that of a discrete symmetry?
Goldstone theorem, especially in the context of condensed matter physics, can be stated as:
Whenever there is spontaneous breakdown of a continuous global symmetry, the spectrum of the theory ...
- 26.8k