Quantum computation with moving quantum dots generated by surface acoustic waves

Abstract

Motivated by recent experimental observations [M. Kataoka et al., Phys. Rev. Lett. 102, 156801 (2009)], we propose here a theoretical approach to implement quantum computation with bound states of electrons in moving quantum dots generated by the driving of surface acoustic waves. Differing from static quantum dots defined by a series of static electrodes above the two-dimensional electron gas (2DEG), here a single electron is captured from a 2DEG reservoir by a surface acoustic wave and then trapped in a moving quantum dot (MQD) transported across a quasi-one-dimensional channel, wherein all the electrons have been excluded by the actions of the surface gates. The flying qubit introduced here is encoded by the two lowest levels of the electron in the MQD, and the Rabi oscillation between these two levels could be implemented by applying finely selected microwave pulses to the surface gates. By using the Coulomb interaction between the electrons in different MQDs, we show that a desirable two-qubit operation, i.e., iswap gate, could be realized. Readouts of the present flying qubits are also feasible with the current single-electron detected technique.