1,507 research outputs found
Tight Bounds on the Synthesis of 3-bit Reversible Circuits: NFT Library
The reversible circuit synthesis problem can be reduced to permutation group.
This allows Schreier-Sims Algorithm for the strong generating set-finding
problem to be used to find tight bounds on the synthesis of 3-bit reversible
circuits using the NFT library. The tight bounds include the maximum and
minimum length of 3-bit reversible circuits, the maximum and minimum cost of
3-bit reversible circuits. The analysis shows better results than that found in
the literature for the lower bound of the cost. The analysis also shows that
there are 1960 universal reversible sub-libraries from the main NFT library.Comment: 18 pages. arXiv admin note: text overlap with arXiv:1101.438
Reading a Single Qubit System Using Weak Measurement with Variable Strength
Acquiring information about an unknown qubit in a superposition of two states
is essential in any computation process. Quantum measurement, or sharp
measurement, is usually used to read the information contents of that unknown
qubit system. Quantum measurement is an irreversible operation that makes the
superposition collapses to one of the two possible states in a probabilistic
way. In this paper, a quantum algorithm will be proposed to read the
information in an unknown qubit without applying sharp measurement on that
qubit. The proposed algorithm will use a quantum feedback control scheme by
applying sharp measurement iteratively on an auxiliary qubit weakly entangled
with the unknown qubit. The information contents of the unknown qubit can be
read by counting the outcomes from the sharp measurement on the auxiliary
qubit. Iterative measurements on the auxiliary qubit will make the amplitudes
of the superposition move in a random walk manner where a weak measurement is
applied on the unknown qubit which can be reversed when the random walk takes
opposite steps to decrease the disturbance introduced to the system. The
proposed algorithm will define the strength of the weak measurement so that it
can be controlled by adding an arbitrary number of dummy qubits to the
system. This will make the measurement process slowdown to an arbitrary scale
so that the effect of the sharp measurement on the unknown qubit is reached
after measurements on the auxiliary qubit.Comment: 15 pages, 4 figure
- …