Possible Analogy between Superfluidity in (4)He and High TemperatureSuperconductivity

摘要

It is generally accepted that the close similarities between superfluid 4He andsuperconductors (e.g. no resistance to flow and macroscopic quantum effects) are due to the fact that both systems contain a Bose-Einstein condensate (BEC), i.e. a macroscopic number of Bosons in a single momentum state. However the phase transition in the two systems appears to be driven by quite different physical mechanisms. In superconductors the electrons must be paired into Bosons before condensation can occur and in standard BCS theory, it is the strength of the pairing interaction which determines the transition temperature TC. On the other hand in 4He, the atoms form essentially indivisible Bose particles in both the normal and superfluid states and hence the binding of the Bosons can play no part in determine TC.