2007/12/06 by E. Räsänen, E. Rasanen, H. Saarikoski +5 · 1 citation
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Condensed matter physics #Electron #Fermi gas #Filling factor #Landau quantization #Physics #Quantum Hall effect #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Quantum spin Hall effect #Semiconductor Quantum Structures and Devices #Spin (aerodynamics) #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.77.041302
published as Phys. Rev. B 77, 041302(R) (2008) · To appear in Phys. Rev. B (Rapid. Comm.)
arxiv created 2007/12/06 · openalex publication_date 2008/01/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Two-dimensional semiconductor quantum dots are studied in the filling-factor range 2<\ensuremathν<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 \ensuremath∼30. We find the onset of the spin-droplet regime at \ensuremathν=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 \ensuremathν=5∕2 quantum Hall state in narrow quantum point contacts.