2005/05/31 by Michael Thorwart, M. Thorwart, J. Eckel +2 · 2 citations
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.72.235320
published as Phys. Rev. B. 72, 235320 (2005) · 5 pages, 7 figures, replaced with the version to appear in Phys. Rev. B
arxiv created 2005/10/24 · openalex publication_date 2005/12/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the dynamics of a double quantum dot charge qubit which is coupled to piezoelectric acoustic phonons, appropriate for GaAs heterostructures. At low temperatures, the phonon bath induces the non-Markovian dynamical behavior of the oscillations between the two charge states of the double quantum dot. Upon applying the numerically exact quasiadiabatic propagator path-integral scheme, the reduced density matrix of the charge qubit is calculated, thereby avoiding the Born-Markov approximation. This allows a systematic study of the dependence of the Q factor on the lattice temperature, on the size of the quantum dots, as well as on the interdot coupling. We calculate the Q factor for a recently realized experimental setup and find that it is two orders of magnitudes larger than the measured value, indicating that the decoherence due to phonons is a subordinate mechanism.