Entanglement and transport through correlated quantum dot

O. Malkoc, C. Bergenfeldt, Peter Samuelsson

Entanglement between spatially separated electrons in nanoscale transport is a fundamental property, yet to be demonstrated experimentally. Here we propose and analyse theoretically the transport statistics of a generic spin entangler coupled to a hybrid quantum dot-ferromagnet detector system. We show that the full distribution of charges arriving at the ferromagnetic terminals provides complete information on the spin state of the particles emitted by the entangler. This provides means for spin entanglement detection via electrical current correlations, with optimal measurement strategies depending on the a priori knowledge of ferromagnet polarization and spin-flip rates in the detector dots. The scheme is exemplified by applying it to Andreev and triple dot entanglers.

A. P. Burgers, John R. Schaibley, Duncan G. Steel

Stefan Legel

Coherence and correlations between electrons in weakly coupled quantum dots are considered in general nonequilibrium situations. The influence of strong onsite Coulomb interaction on the evolution of the density matrix of a system of coherently coupled quantum dots and on the coherence of the transport is investigated. It turns out, that spin entanglement between electrons on spatially separated quantum dots can be induced in nonequilibrium. We study in detail the precursors of this phenomenon.

Constantine Yannouleas, Uzi Landman

Hai‐Feng Lü, Yong Guo, Lian-Fu Wei

The authors investigate current noise cross correlations (CCs) through coupled double quantum dots under transport conditions. It is demonstrated that positive CCs relate to either thermal fluctuations at nonzero temperature or quantum tunneling processes at zero temperature. These measurable CCs could service as the sensitive indicators of entanglements between electronic spins in double dots coupled by exchange interactions.