Condensed Matter Physics

COnDEnsED MattEr PhysICs

COnDEnsED MattEr PhysICs

Physics , Condensed Matter Homework

The key insight of Bogoliubov is that although the mean-field Hamiltonian (1) is clearly not diagonal in the space of states created by the operators ck,↑/↓, it may be diagonal in a basis of states created by operators related to these via a simple SU2 transformation. Indeed, it may be the case that ‘electrons’ and ‘holes’ are the wrong degrees of freedom to consider; we should at least look to...

Introduction to Condensed Matter Physics

Majorana and Condensed Matter Physics

1. Spin Response and Universal Connection In [1], Majorana considered the coupling of spins to magnetic fields. The paper is brief, but it contains two ingenious ideas whose importance extends well beyond the immediate problem he treated, and should be part of every physicists’ toolkit. The first of those ideas, is that having solved the problem for spin 12 , one can deduce the solution for gen...