Why the trailing electron in the cooper pair doesnot cause any lattice distortion?

Nivas Ramachandiran @Nivas_Ramachandiran

03 March 2017 1 2K Report

Only two electrons act in a co-ordinated way. Why this is not extended to an infinite chain of electrons?

Two electrons can form Copper pair if theirs momenta k1 and k2 and spins are exactly opposite (in triplet pairs the spins can identical). Thus the condition for pairing is: k1+k2=0 or k1=-k2 (in vector notation). The probability of pairing of electrons with momenta that don’t fulfill this condition is negligible (see BCS theory). Moreover, because of Pauli exclusion principle in the population of electrons there can’t exist two or more electrons with the same momenta and spins. This explains why electron pairs and nor triplets, quadruplets or chains are formed in a condensate.

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