(c) In a superconductor at sufficiently low temperature, electrons form pairs that occupy a ground state with an energy
Posted: Fri May 06, 2022 6:27 am
(c) In a superconductor at sufficiently low temperature, electrons form pairs that occupy a ground state with an energy defined as € = 0. The lowest-energy excited state can only be accessed by breaking these pairs, at a cost of Ae per electron. We here consider the limit kÅT < A€, such that we can ignore all higher excited states and can assume that electrons only occupy states with energies 0 and Ae. [2] i. Explain in a few words why electron pair formation is a requirement for superconductivity to occur. [6] ii. Show that in this limit (kgT << Ae), the heat capacity of a superconductor due to these electrons obeys Δε Δε Cx (4€) ² • (-/B7). T KBT [3] iii. In this limit, compare the heat capacity of a superconductor with that of a metal, sketching them together in an annotated plot. exp