Freiburg 2019 – wissenschaftliches Programm

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FM: Fall Meeting

FM 38: Enabling Technologies: Quantum Dots, Quantum Wires, Point Contacts and Excitonic Systems

FM 38.7: Talk

Dienstag, 24. September 2019, 15:30–15:45, 3043

Quantum State Transfer in Quantum Dot Arrays — Jordi Picó-Cortés, Yue Ban, Sigmund Kohler, and •Gloria Platero — Instituto de Ciencia de Madrid, CSIC

The effect of ac electric fields on the transport properties of low dimensional systems has been a topic of intense research in the last years. Applying ac electric fields to coupled quantum dots allows to transfer charge between them by means of photo-assisted transitions. Experiments in triple quantum dots unambiguously show direct electron transfer between the outer dots, without the participation of the intermediate region other than virtual, thus minimizing the effect of decoherence and relaxation . In the presence of ac driving the direct transfer of electrons between distant dots takes place by means of photo-assisted virtual transitions. I will focus on a protocol for preparing a quantum state at the left edge of a triple quantum dot and directly transferring it to the right edge by means of ac gate voltages. I will show that by the controlled generation of dark states it is possible to increase the fidelity of the transfer protocol . I will discuss as well other protocols which allow for long range charge transfer in quantum dot arrays, as coherent transfer by adiabatic passage (CTAP). I will show how these protocols can be speeded up by shortcuts of adiabaticity. Furthermore, it allows for long range transfer of two electron entangled states in quantum dot arrays with high fidelity. The proposed protocols offer an alternative and robust mechanism for quantum information processing.