Suppressing charge noise decoherence in superconducting charge qubits

Circuit theory for decoherence in superconducting charge qubits

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...

Superconducting Qubits Ii : Decoherence

This is an introduction to elementary decoherence theory as it is typically applied to superconducting qubits. Abbreviations: SQUID – superconducting quantum interference device; qubit – quantum bit; TSS – two state system

Improving intrinsic decoherence in multiple-quantum-dot charge qubits

Martina Hentschel,1 Diego C. B. Valente,2 Eduardo R. Mucciolo,2 and Harold U. Baranger3 1Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, D-1187 Dresden, Germany 2Department of Physics, University of Central Florida, P.O. Box 162385, Orlando, Florida 32816-2385 USA 3Department of Physics, Duke University, P.O. Box 90305, Durham, North Carolina 27708-0305, USA Received 28 ...

Phonon-induced decoherence and dissipation in donor-based charge qubits

We investigate the phonon-induced decoherence and dissipation in a donor-based charge quantum bit realized by the orbital states of an electron shared by two dopant ions which are implanted in a silicon host crystal. The dopant ions are taken from the group-V elements Bi, As, P, Sb. The excess electron is coupled to deformation potential acoustic phonons which dominate in the Si host. The parti...

Low temperature decoherence and relaxation in charge Josephson junction qubits