Weak values of electron spin in a double quantum dot.
We propose a protocol for a controlled experiment to measure a weak value of the electron's spin in a solid state device. The weak value is obtained by a two step procedure--weak measurement followed by a strong one (postselection), where the outcome of the first measurement is kept provided a second postselected outcome occurs. The setup consists of a double quantum dot and a weakly coupled quantum point contact to be used as a detector. Anomalously large values of the spin of a two electron system are predicted, as well as negative values of the total spin. We also show how to incorporate the adverse effect of decoherence into this procedure.
Romito
Alessandro
A
Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot 76100, Israel.
Gefen
Yuval
Y
Blanter
Yaroslav M
YM