Quantum Optics with Single-Electron Charged Quantum Dots

A. Beveratos, Izo I. Abram, Jean‐Michel Gérard +1 more

Vasileios N. Stavrou, Xuedong Hu

We investigate electron charge decoherence in a laterally coupled single-electron semiconductor double quantum dot through electron-phonon interaction. We analytically and numerically evaluate the relaxation and dephasing rates due to electron coupling to both acoustic and optical phonons, and explore the system parameter space in terms of interdot distance, strength of single-dot confinement, and interdot coupling strength. Our numerical results show that the electron scattering rates are strongly dependent on the strength of the electron confinement and the size of the system. In addition, although the most dominant factor that determines the charge decoherence rate is the energy splitting between the charge qubit states, the details of the double dot configuration are also very important.

Mauricio Garrido

Alexander V. Tsukanov, I. Yu. Kateev

We consider the possibility of using optical vibrational degrees of freedom as an additional resource for controlling the evolution of a charge qubit based on a semiconductor single-electron double quantum dot. The effect of electron – photon – phonon processes on the accuracy of single-qubit operations is investigated. It is shown that, depending on the phonon decay rate and detuning of the electronic transition frequency from the optical phonon frequency, these processes can both facilitate and prevent coherent electron transfer between quantum dots.

Yinyu Liu

Erik D. Kim, Katherine Smirl, Yanwen Wu +6 more

We demonstrate the all-optical ultrafast manipulation and read-out of optical transitions in a single negatively charged self-assembled InAs quantum dot, an important step towards ultrafast control of the resident spin. Experiments performed at zero magnetic field show the excitation and decay of the trion (negatively charged exciton) as well as Rabi oscillations between the electron and trion states. Application of a DC magnetic field perpendicular to the growth axis of the dot enables observation of a complex quantum beat structure produced by independent precession of the ground state electron and the excited state heavy hole spins.