Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2004-11-17
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
26 pages, 8 figures
Scientific paper
Quantum information processing has greatly increased interest in the phenomenon of environmentally-induced decoherence. The spin boson model is widely used to study the interaction between a spin-modelling a quantum particle moving in a double well potential-and its environment-modelled by a heat bath of harmonic oscillators. This paper extends a previous analysis of the static spin boson study to the driven spin boson case, with the derivation of an exact integro-differential equation for the time evolution of the propagator of the reduced spin density matrix. This is the first main result. By specializing to weak damping we then obtain the next result, a set of Bloch-Redfield equations for the equilibrium fixed spin initial condition. Finally we show that these equations can be used to solve the classic dissipative Landau-Zener problem and illustrate these solutions for the weak damping case. The effect of dissipation is seen to be minimised as the speed of passage is increased, implying that qubits need to be switched as fast as possible.
Watkins Nicholas Wynn
Waxman David
No associations
LandOfFree
Path integral derivation of Bloch-Redfield equations for a qubit weakly coupled to a heat bath: Application to nonadiabatic transitions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Path integral derivation of Bloch-Redfield equations for a qubit weakly coupled to a heat bath: Application to nonadiabatic transitions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Path integral derivation of Bloch-Redfield equations for a qubit weakly coupled to a heat bath: Application to nonadiabatic transitions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-654630