- #1
fluidistic
Gold Member
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I am wondering what is the physical evidence that Cooper pairs are indeed the ones responsible for superconductivity. These pairs consist of two electrons with opposite momentum, forming a boson with null momentum.
But what about pairs that would consist of, say, 6 electrons (or even more)? Of these 6 electrons, 3 (with momenta -p, -p, +p) would form a fermion with momentum -p while the 3 other electrons would form a fermion with momentum +p (because of -p, +p, +p). Hence such a pair would also form a boson with null momentum, just like a Cooper pair does.
I could understand that since the pairs are formed with an interaction between electrons via virtual phonons, such a pair would be much less likely to form than a regular Cooper pair. But is the probability of such a pair to form exactly 0? If not, would such a pair contribute to superconductivity? I guess not, since it is claimed everywhere that only Cooper pairs are responsible for superconductivity.
So, which phenomenon, or experiment, invalidates all other possible pairing of electrons? Or what prediction(s) would such pairs do that doesn't match experiments?
But what about pairs that would consist of, say, 6 electrons (or even more)? Of these 6 electrons, 3 (with momenta -p, -p, +p) would form a fermion with momentum -p while the 3 other electrons would form a fermion with momentum +p (because of -p, +p, +p). Hence such a pair would also form a boson with null momentum, just like a Cooper pair does.
I could understand that since the pairs are formed with an interaction between electrons via virtual phonons, such a pair would be much less likely to form than a regular Cooper pair. But is the probability of such a pair to form exactly 0? If not, would such a pair contribute to superconductivity? I guess not, since it is claimed everywhere that only Cooper pairs are responsible for superconductivity.
So, which phenomenon, or experiment, invalidates all other possible pairing of electrons? Or what prediction(s) would such pairs do that doesn't match experiments?