Suppression of 1/f noise in one-qubit systems
Abstract
We investigate the generation of quantum operations for one-qubit systems under classical noise with 1/fα power spectrum, where 2>α > 0. We present an efficient way to approximate the noise with a discrete multi-state Markovian fluctuator. With this method, the average temporal evolution of the qubit density matrix under 1/fα noise can be feasibly determined from recently derived deterministic master equations. We obtain qubit operations such as quantum memory and the NOTgate to high fidelity by a gradient based optimization algorithm. For the NOT gate, the computed fidelities are qualitatively similar to those obtained earlier for random telegraph noise. In the case of quantum memory however, we observe a nonmonotonic dependency of the fidelity on the operation time, yielding a natural access rate of the memory.