Quantum manipulation of two-electron spin states in metastable double   quantum dots
  We studied experimentally the dynamics of the exchange interaction between two antiparallel electron spins in a so-called metastable double quantum dot where coupling to the electron reservoirs can be ignored. We demonstrate that the level of control of such a double dot is higher than in conventional double dots. In particular, it allows to couple coherently two electron spins in an efficient manner following a scheme initially proposed by Loss and DiVincenzo. The present study demonstrates that metastable quantum dots are a possible route to increase the number of coherently coupled quantum dots. 
Benoit Bertrand, Hanno Flentje, Shintaro Takada, Michihisa Yamamoto,   Seigo Tarucha, Arne Ludwig, Andreas D. Wieck, Christo...
cond-mat.mes-hall