Charge qubits in semiconductor quantum computer architecture: Tunnel coupling and decoherence

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

Decoherence processes during optical manipulation of excitonic qubits in semiconductor quantum dots

Q. Q. Wang,1,2,3 A. Muller,1 P. Bianucci,1 E. Rossi,1 Q. K. Xue,2 T. Takagahara,4 C. Piermarocchi,5 A. H. MacDonald,1 and C. K. Shih1,* 1Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA 2International Center for Quantum Structures (ICQS), Institute of Physics, The Chinese Academy of Sciences, Beijing 100080, People’s Republic of China 3Department of Physics, Wuhan ...

Quantitative evaluation of decoherence and applications for quantum-dot charge qubits

We review results on evaluation of loss of information in quantum registers due to their interactions with the environment. It is demonstrated that an optimal measure of the level of quantum noise e ects can be introduced via the maximal absolute eigenvalue norm of deviation of the density matrix of a quantum register from that of ideal, noiseless dynamics. For a semiconductor quantum dot charg...