Current focusing in InSb heterostructures

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 34; no. 1; pp. 647 - 650
• Main Authors: Dedigama, A.R., Deen, D., Murphy, S.Q., Goel, N., Keay, J.C., Santos, M.B., Suzuki, K., Miyashita, S., Hirayama, Y.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2006; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dresselhaus effect; Electron focusing; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; InSb; Physics; Electron focusing; Dresselhaus effect; 73.63.Hs; 72.80.Ey; InSb; 72.20.Fr; 72.25.Dc; 73.23.Ad; Two-dimensional systems; Indium antimonides; Quantum dots; Doping; Magnetic field effects; Spin polarization; High temperature; Substructure; 72.20.Fr; 72.25.Dc; 72.80.Ey; 73.23.Ad; 73.63.Hs; Electron focusing; Dresselhaus effect; InSb; Focusing; Spin-orbit interactions; Transport processes; Aluminium antimonides; Heterostructures
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2006.03.050

We report transverse electron focusing in a symmetrically doped, InSb-based two-dimensional electron system. In a focusing device, the application of a perpendicular magnetic field steers the electron current from an injecting quantum point contact into a collector quantum point contact whenever the diameter of the cyclotron orbit corresponds to an integer fraction of the injector to collector spatial separation. In low-temperature measurements of in-plane gated devices, we observe peaks in the collector voltage at magnetic fields where focusing is expected. The first peak displays substructure which is preserved at temperatures as high as 10 K and under a variety of gating conditions. We speculate that this substructure originates from spatially distinct paths for electrons with different spin polarizations arising from the large Dresselhaus effect expected for InSb-based electron systems.