In two-level approximation, we investigate the influence of mutual inductive coupling in superconducting quantum circuits on the decoherence of flux qubits under sub-Ohmic thermal bath environment by utilizing Bloch-Redfield function. The investigation results show: (1) The memory effect existing in the solid-state environment is beneficial to prolong the decoherence time of the superconducting flux qubit, building sub-Ohmic thermal bath environments can improve the decoherence of the solid-state qubit. (2) When the quantum system and the thermal bath are in weak coupling, generally speaking, the mutual coupling effect between circuit elements will destroy the quantum coherence; but when the quantum system and the thermal bath are in strong coupling, it will help to enhance the decoherence time by controlling the mutual inductive coupling between the loop components.In two-level approximation, we investigate the influence of mutual inductive coupling in superconducting quantum circuits on the decoherence of flux qubits under sub-Ohmic thermal bath environment by utilizing Bloch-Redfield function. The investigation results show: (1) The memory effect existing in the solid-state environment is beneficial to prolong the decoherence time of the superconducting flux qubit, building sub-Ohmic thermal bath environments can improve the decoherence of the solid-state qubit. (2) When the quantum system and the thermal bath are in weak coupling, generally speaking, the mutual coupling effect between circuit elements will destroy the quantum coherence; but when the quantum system and the thermal bath are in strong coupling, it will help to enhance the decoherence time by controlling the mutual inductive coupling between the loop components.

Advanced materials researchJun 1, 20130 citations

Quantum energy decays and decoherence in discrete baths

Mircea Daniel Galiceanu, Marcus W. Beims, Walter T. Strunz

The quantum average energy decay and the purity decay are studied for a system particle as a function of the number of constituents of a discrete bath model. The system particle is subjected to two distinct physical situations: the harmonic oscillator (HO) and the Morse potential. The environment (bath) is composed by a {\it finite} number N of uncoupled HOs, characterizing the structured bath, which in the limit $N\to\infty$ is assumed to have an ohmic, sub-ohmic or super-ohmic spectral density. For very low values of N the mean energy and purity remain constant in time but starts to decay for intermediate values (10The quantum average energy decay and the purity decay are studied for a system particle as a function of the number of constituents of a discrete bath model. The system particle is subjected to two distinct physical situations: the harmonic oscillator (HO) and the Morse potential. The environment (bath) is composed by a {\it finite} number N of uncoupled HOs, characterizing the structured bath, which in the limit $N\to\infty$ is assumed to have an ohmic, sub-ohmic or super-ohmic spectral density. For very low values of N the mean energy and purity remain constant in time but starts to decay for intermediate values (10

arXiv:1111.0243Nov 1, 20110 citations

Quantum control and quantum measurement in solid state qubits

Luca Chirolli

Jan 1, 20100 citations

N\to\infty

is assumed to have an ohmic, sub-ohmic or super-ohmic spectral density. For very low values of N the mean energy and purity remain constant in time but starts to decay for intermediate values (10