Zeeman coherence in single quantum dots

Takagahara

Gang Chen

K. Berrada

Gang Chen, E. Tabak, Duncan G. Steel +4 more

Summary form only given. We report the observation of an interesting coherent effect, which looks very much like the so-called Zeeman coherence in atomic physics and is indeed an optically induced entanglement between two oppositely oriented electrons confined to one single QD. This is the first observation of entanglement in semiconductors and is an important step in realizing a quantum logic device such as proposed for quantum computing.

Parvendra Kumar, Takashi Nakajima

We demonstrate the coherent population trapping in a single quantum dot and an ensemble of negatively charged quantum dots using a train of femtosecond pulses. Particularly in an ensemble of quantum dots, we show that the detrimental effects due to the inhomogeneous distribution of their properties can be minimized by appropriately choosing the pulse-train parameters and the magnetic-field strength in such a way that the electron-Zeeman splitting is an integer multiple of the pulse repetition rate.