Phonon-induced decoherence of the two-level quantum subsystem due to relaxation and dephasing processes
arXiv:0802.0243 · doi:10.1016/j.physleta.2008.01.064
Abstract
Phonon-related decoherence effects in a quantum double-well two-level subsystem coupled to a solid are studied theoretically by the example of deformation phonons. Expressions for the reduced density matrix at T=0 are derived beyond the Markovian approximation by means of explicit solution of the non-stationary Schrodinger equation for the interacting electron-phonon system at the initial stage of its evolution. It is shown that as long as the difference between the energies of the electron in the left and the right well greatly exceeds the energy of the electron tunneling between the minima of the double-well potential, decoherence is primarily due to dephasing processes. This case corresponds to a strongly asymmetric potential and spatially separated eigenfunctions localized in the vicinity of one or another potential minimum. In the opposite case of the symmetric potential, the decoherence stems from the relaxation processes, which may be either "resonant" (at relatively long times) or "nonresonant" (at short times), giving rise to qualitatively different temporal evolution of the electron state. The results obtained are discussed in the context of quantum information processing based on the quantum bits encoded in electron charge degrees of freedom.
20 pages, no figures
References in corpus (29)
- Coherent manipulation of electronic states in a double quantum dot
- Manipulation of a single charge in a double quantum dot
- Spontaneous Emission Spectrum in Double Quantum Dot Devices
- Charge-qubit operation of an isolated double quantum dot
- Atomically precise placement of single dopants in Si
- Charge-based quantum computing using single donors in semiconductors
- Coherent control of tunneling in a quantum dot molecule
- Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum Dot
- Quantum gates by coupled asymmetric quantum dots and controlled-NOT-gate operation
- Decoherence Rate of Semiconductor Charge Qubit Coupled to Acoustic Phonon Reservoir
- Rigorous Born Approximation and beyond for the Spin-Boson Model
- Adiabatic Transfer of Electrons in Coupled Quantum Dots
- Resonant nature of phonon-induced damping of Rabi oscillations in quantum dots
- Charge decoherence in laterally coupled quantum dots due to electron-phonon interactions
- Measuring the decoherence rate in a semiconductor charge qubit
- Adiabatic Decoherence
- Resonant electron transfer between quantum dots
- Phonon Decoherence of a Double Quantum Dot Charge Qubit
- Non-Markovian dynamics of double quantum dot charge qubits due to acoustic phonons
- Charge qubit dynamics in a double quantum dot coupled to phonons
- Universal Decoherence in Solids
- Rabi oscillations in the four-level double-dot structure under the influence of the resonant pulse
- Optically Driven Qubits in Artificial Molecules
- Single-qubit operations in the double-donor structure driven by strongly detuned optical pulses
- Single-qubit operations in the double-donor structure driven by optical and voltage pulses
- Resonant-pulse operations on the buried donor charge qubits in semiconductors
- Non-markovian dynamics of double quantum dot charge qubit with static bias
- Comment on "Universal Decoherence in Solids"
- Auxiliary-level-assisted operations with charge qubits in semiconductors