Coherent manipulation of charge qubits in double quantum dots

Abstract

The coherent time evolution of electrons in double quantum dots induced by fast bias-voltage switches is studied theoretically. As it was shown experimentally, such driven double quantum dots are potential devices for controlled manipulation of charge qubits. By numerically solving a quantum master equation we obtain the energy- and time-resolved electron transfer through the device which resembles the measured data. The observed oscillations are found to depend on the level offset of the two dots during the manipulation and, most surprisingly, also the on initialization stage. By means of an analytical expression, obtained from a large-bias model, we can understand the prominent features of these oscillations seen in both the experimental data and the numerical results. These findings strengthen the common interpretation in terms of a coherent transfer of electrons between the dots.

18 pages, 4 figures

References in corpus (6)

• Driven coherent oscillations of a single electron spin in a quantum dot
• The influence of ultra-fast laser pulses on electron transfer in molecular wires studied by a non-Markovian density matrix approach
• Phonon Decoherence of a Double Quantum Dot Charge Qubit
• Transient regime in non-linear transport through many-level quantum dots
• A partial fraction decomposition of the Fermi function
• Ultrafast manipulation of electron spins in a double quantum dot device: A real-time view