Collapse of the spin-singlet phase in quantum dots

• Published in: Physical review letters Vol. 88; no. 25 Pt 1; p. 256804
• Main Authors: Ciorga, M, Wensauer, A, Pioro-Ladriere, M, Korkusinski, M, Kyriakidis, J, Sachrajda, A S, Hawrylak, P
• Format: Journal Article
• Language: English
• Published: United States 24-06-2002
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.88.256804

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.