Optimal generation of single-qubit operation from an always-on interaction by algebraic decoupling

Optimal generation of single-qubit operation from an always-on interaction by algebraic decoupling

We present a direct algebraic decoupling approach to generate arbitrary single-qubit operations in the presence of a constant interaction by application of local control signals. To overcome the difficulty of undesirable entanglement generated by the untunable interaction, we use an algebraic approach to decouple the two-qubit Hamiltonian into two single-qubit Hamiltonians and the desired singl...

Near-optimal dynamical decoupling of a qubit.

We present a near-optimal quantum dynamical decoupling scheme that eliminates general decoherence of a qubit to order n using O(n2) pulses, an exponential decrease in pulses over all previous decoupling methods. Numerical simulations of a qubit coupled to a spin bath demonstrate the superior performance of the new pulse sequences.

Controlling qubit arrays with anisotropic XXZ Heisenberg interaction by acting on a single qubit

We investigate anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on one of the end spins, with the aim of exploring local quantum control in arrays of interacting qubits. In this work, which uses a recent Lie-algebraic result on the local controllability of spin chains with “alwayson” interactions, we determine piecewise-constant control pulses corresponding to optimal fidel...

Optimal discrimination of single-qubit mixed states

Degree of Optimality as a Measure of Distance of Power System Operation from Optimal Operation

This paper presents an algorithm based on inter-solutions of having scheduled electricity generation resources and the fuzzy logic as a sublimation tool of outcomes obtained from the schedule inter-solutions. The goal of the algorithm is to bridge the conflicts between minimal cost and other aspects of generation. In the past, the optimal scheduling of electricity generation resources has been ...