Collapse of the spin-singlet phase in quantum dots.
We present experimental and theoretical results on a new regime in quantum dots in which the filling factor two-singlet state is replaced by new spin polarized phases. We make use of spin blockade spectroscopy to identify the transition to this new regime as a function of the number of electrons. The key experimental observation is a reversal of the phase in the systematic oscillation of the amplitude of Coulomb blockade peaks as the number of electrons is increased above a critical number. It is found theoretically that correlations are crucial to the existence of the new phases.
Ciorga
M
M
Institute for Microstructural Science, Research Council of Canada, Ottawa, Canada K1A OR6.
Wensauer
A
A
Pioro-Ladriere
M
M
Korkusinski
M
M
Kyriakidis
J
J
Sachrajda
A S
AS
Hawrylak
P
P