Jeudi 19 juin 2014 à 10h15
Salle 234, Ecole de Physique

Long distance tunneling in triple quantum dots

Rafael Sanchez, ICMM-CSIC, Spain

Quantum mechanics allows for superpositions of indirectly coupled states even if the intermediate states are far in energy. This is done via superexchange: higher order transitions in which the energetically forbidden intermediate states are only virtually occupied. I will discuss the minimal system with long range superexchange interactions affected by spin correlations in a triple quantum dot. Evidences of such transitions have been recently reported in transport experiments [1,2] and confirmed by real time charge detection [3]. We are interested in a configuration where the two paths with different virtual intermediate states are possible and lead to quantum interference. Remarkably, we find conditions where the destructive interference of these transitions completely cancels the transport, what we call superexchange blockade [4]. hfillreak [1] M. Busl et al., Nature Nanotech. 8, 261 (2013). [2] R. S