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arXiv · 0712.0991

Spin-droplets in confined quantum Hall systems

E. Rasanen·H. Saarikoski·A. Harju·M. Ciorga·A. S. Sachrajda
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Abstract

Two-dimensional semiconductor quantum dots are studied in the the filling-factor range 2<v<3. We find both theoretical and experimental evidence of a collective many-body phenomenon, where a fraction of the trapped electrons form an incompressible spin-droplet on the highest occupied Landau level. The phenomenon occurs only when the number of electrons in the quantum dot is larger than ~30. We find the onset of the spin-droplet regime at v=5/2. This proposes a finite-geometry alternative to the Moore-Read-type Pfaffian state of the bulk two-dimensional electron gas. Hence, the spin-droplet formation may be related to the observed fragility of the v=5/2 quantum Hall state in narrow quantum point contacts.

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E. Rasanen, H. Saarikoski, A. Harju, M. Ciorga, A. S. Sachrajda. 2007-12-06. Spin-droplets in confined quantum Hall systems. https://doi.org/10.1103/physrevb.77.041302

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