caa a22 4500 445886714 CHVBK 20180317145602.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s11128-010-0224-8 doi (NATIONALLICENCE)springer-10.1007/s11128-010-0224-8 Studies in a random noise model of decoherence [Elektronische Daten] [P. Korcyl, J. Wosiek, L. Stodolsky] We study the effects of noise and decoherence for a double-potential well system, suitable for the fabrication of qubits and quantum logic elements. A random noise term is added to the hamiltonian, the resulting wavefunction found numerically and the density matrix obtained by averaging over noise signals. Analytic solutions using the two-state model are obtained and found to be generally in agreement with the numerical calculations. In particular, a simple formula for the decoherence rate in terms of the noise parameters in the two-state model is reviewed and verified for the full simulation with the multi-level system. The formalism is extended to describe multiple sources of noise or different "dephasing” axes at the same time. Furthermore, the old formula for the "Turing-Watched Pot” effect is generalized to the case where the environmental interactions do not conserve the "quality” in question. Various forms for the noise signal are investigated. An interesting result is the importance of the noise power at low frequency. If it vanishes there is, in leading order, no decoherence. This is verified in a numerical simulation where two apparently similar noise signals, but differing in the power at zero frequency, give strikingly different decoherence effects. A short discussion of situations dominated by low frequency noise is given. Springer Science+Business Media, LLC, 2011 Decoherence nationallicence Noise nationallicence Korcyl P. M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059, Cracow, Poland aut Wosiek J. M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059, Cracow, Poland aut Stodolsky L. Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805, Munich, Germany aut Quantum Information Processing Springer US; http://www.springer-ny.com 10/5(2011-10-01), 671-695 1570-0755 10:5<671 2011 10 11128 https://doi.org/10.1007/s11128-010-0224-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11128-010-0224-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Korcyl P. M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059, Cracow, Poland aut NATIONALLICENCE 700 1- Wosiek J. M. Smoluchowski Institute of Physics, Jagellonian University, Reymonta 4, 30-059, Cracow, Poland aut NATIONALLICENCE 700 1- Stodolsky L. Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805, Munich, Germany aut NATIONALLICENCE 773 0- Quantum Information Processing Springer US; http://www.springer-ny.com 10/5(2011-10-01), 671-695 1570-0755 10:5<671 2011 10 11128 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer