  The idea of the quantum computation is based on paradoxical principles of
quantum physics, superposition and entanglement of quantum states. This idea
looks well-founded on the microscopic level in spite of the absence of an
universally recognized interpretation of these paradoxical principles since
they were corroborated over and over again by reliable experiments on the
microscopic level. But the technology can not be able in the near future to
work on the microscopic level. Therefore macroscopic quantum phenomenon -
superconductivity is very attractive for the realization of the idea of quantum
computer. It is shown in the present paper that a chain of superconducting
loops can be only possible quantum register. The proposals by some authors to
provide the EPR correlation with help of a classical interaction witness the
misunderstanding of the entanglement essence. The problem of the possibility of
superposition of macroscopically distinct states is considered.
