  Superconducting loop interrupted by one or three Josephson junctions is
considered in many publications as a possible quantum bit, flux qubit, which
can be used for creation of quantum computer. But the assumption on
superposition of two macroscopically distinct quantum states of superconducting
loop contradict to the fundamental law of angular momentum conservation and the
universally recognized quantum formalism. Numerous publications devoted to the
flux qubit testify to an inadequate interpretation by many authors of
paradoxical nature of superposition principle and the subject of quantum
description.
