Abstract:
Strong electron and spin correlations in a
double quantum dot (DQD) can give rise to
different quantum states.We observe a
continuous transition from a Kondo state
exhibiting a single-peak Kondo
resonance to another exhibiting a double
peak by increasing the interdot coupling (t)
in a parallel-coupled DQD. The transition
into the double-peak state provides evidence
for spin entanglement between the excess
electrons on each dot. Toward the
transition, the peak splitting merges and
becomes substantially smaller than t because
of strong Coulomb effects. Our device
tunability bodes well for future quantum
computation applications.