In an actual superconductor, the charged particles are electrons, which are fermions not bosons. So in order to have superconductivity, the electrons need to somehow bind into Cooper pairs . The charge of the condensate q is therefore twice the electron charge − e . The pairing in a normal superconductor is due to lattice vibrations, and is in fact very weak; this means that the pairs are very loosely bound. The description of a Bose–Einstein condensate of loosely bound pairs is actually more difficult than the description of a condensate of elementary particles, and was only worked out in 1957 by Bardeen, Cooper and Schrieffer in the famous BCS theory.
Defense mechanism , in psychoanalytic theory, any of a group of mental processes that enables the mind to reach compromise solutions to conflicts that it is unable to resolve. The process is usually unconscious , and the compromise generally involves concealing from oneself internal drives or feelings that threaten to lower self-esteem or provoke anxiety . The concept derives from the psychoanalytic hypothesis that there are forces in the mind that oppose and battle against each other. The term was first used in Sigmund Freud ’s paper “ The Neuro-Psychoses of Defence ” (1894).