Spatial decoherence factor via the qubit-field interaction

Spatial decoherence factor via the qubit - field interaction

We analyze the time evolution of an initial spatial coherence for a two level atom whose internal degrees of freedom interact with a single mode of a cavity field. When the qubit-field subsystem is taken as an environment, the translational dynamics experiences a decoherence process which may be encoded in a decoherence factor D. We find that the field statistics affects D through the alternati...

Two-qubit decoherence mechanisms revealed via quantum process tomography

We analyze the quantum process tomography QPT in the presence of decoherence, focusing on distinguishing local and nonlocal decoherence mechanisms for a two-partite system from experimental QPT data. In particular, we consider the iSWAP gate realized with superconducting phase qubits and calculate the QPT matrix in the presence of several local and nonlocal decoherence processes. We determine s...

Low-decoherence flux qubit

J. Q. You,1,2 Xuedong Hu,3 S. Ashhab,2 and Franco Nori2,4 1Department of Physics and Surface Physics Laboratory (National Key Laboratory), Fudan University, Shanghai 200433, China 2Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako-shi 351-0198, Japan 3Department of Physics, University at Buffalo, SUNY, Buffalo, New York 14260-1500, USA 4Center for Theoretic...

Optimal dynamical decoherence control of a qubit.

We present a theory of dynamical control by modulation for optimal decoherence reduction. The theory is based on the non-Markovian Euler-Lagrange equation for the energy-constrained field that minimizes the average dephasing rate of a qubit for any given dephasing spectrum.

One , Two , and n Qubit Decoherence