2004/08/31 by Guido Burkard
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.supr-con #quant-ph
paper · pdf · doi:10.1103/physrevb.71.144511
published as Phys. Rev. B 71, 144511 (2005) · 8 pages, 3 figures; v2: published version; typo in Eq.(30) corrected, minor changes, reference added
arxiv created 2005/04/28 · arxiv updated 2009/12/01
Based on a network graph analysis of the underlying circuit, a quantum theory of arbitrary superconducting charge qubits is derived. Describing the dissipative elements of the circuit with a Caldeira-Leggett model, we calculate the decoherence and leakage rates of a charge qubit. The analysis includes decoherence due to a dissipative circuit element such as a voltage source or the quasiparticle resistances of the Josephson junctions in the circuit. The theory presented here is dual to the quantum circuit theory for superconducting flux qubits. In contrast to spin-boson models, the full Hilbert space structure of the qubit and its coupling to the dissipative environment is taken into account. Moreover, both self and mutual inductances of the circuit are fully included.