arXiv:cond-mat/0603363 · Physical Review B

Spin entanglement induced by spin-orbit interactions in coupled quantum dots

Nan Zhao, L. Zhong, Jia‐Lin Zhu, C. P. Sun

Published Aug 3, 2006• 22 citations

Abstract

We theoretically explore the possibility of creating spin quantum entanglement in a system of two electrons confined respectively in two vertically coupled quantum dots in the presence of Rashba-type spin-orbit coupling. We find that the system can be described by a generalized Jaynes-Cummings model of two-mode bosons interacting with two spins. The lower excited states of this model are calculated to reveal the underlying physics of the far-infrared absorption spectra. The analytic perturbation approach shows that an effective transverse coupling of spins can be obtained by eliminating the orbital degrees of freedom in the large-detuning limit. Here, the orbital degrees of freedom of the two electrons, which are described by two-mode bosons, serve as a quantized data bus to exchange the quantum information between the two electron spins. Then a nontrivial two-qubit logic gate is realized and spin entanglement between the two electrons is created by virtue of spin-orbit interactions.

DOI: 10.1103/physrevb.74.075307

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