Decoherence of quantum gates based on Aharonov-Anandan phases in a multistep scheme
1 State Key Laboratory of Surface Physics and Department of Physics, Fudan University Shanghai, 200433, China
2 Faculty of Science, Kunming University of Science and Technology - Kunming, 650093, China
Received: 6 February 2013
Accepted: 17 May 2013
We study quantum decoherence of single-qubit and two-qubit Aharonov-Anandan (AA) geometric phase gates realized in a multistep scheme. Each AA gate is also compared with the dynamical phase gate performing the same unitary transformation within the same time period and coupled with the same environment, which is modeled as harmonic oscillators. It is found that the fidelities and the entanglement protection of the AA phase gates are enhanced by the states being superpositions of different eigenstates of the environmental coupling, and the noncommutativity between the qubit interaction and the environmental coupling.
PACS: 03.67.Lx – Quantum computation architectures and implementations / 03.65.Vf – Phases: geometric; dynamic or topological / 03.67.Pp – Quantum error correction and other methods for protection against decoherence
© EPLA, 2013