1 research outputs found
Storing unitary operators in quantum states
We present a scheme to store unitary operators with self-inverse generators
in quantum states and a general circuit to retrieve them with definite success
probability. The continuous variable of the operator is stored in a
single-qubit state and the information about the kind of the operator is stored
in classical states with finite dimension. The probability of successful
retrieval is always 1/2 irrespective of the kind of the operator, which is
proved to be maximum. In case of failure, the result can be corrected with
additional quantum states. The retrieving circuit is almost as simple as that
which handles only the single-qubit rotations and CNOT as the basic operations.
An interactive way to transfer quantum dynamics, that is, to distribute
naturally copy-protected programs for quantum computers is also presented using
this scheme.Comment: 4 pages, 3 figures, errors in Eq. (8) and Fig. 3 are fixed, to appear
in Phys. Rev.