Title :
All-electric dual-QPC spin polarizer and analyzer
Author :
Wan, J. ; Cahay, M. ; Debray, P. ; Newrock, R.S.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Cincinnati, Cincinnati, OH, USA
Abstract :
The ballistic conductance of a device consisting of two quantum point contacts, separated by a distance smaller than the spin coherence length, has been measured at 4.2K. A conductance plateau at 0.5 (2e2/h) is observed in the absence of external magnetic field indicating spontaneous spin polarization. This happens when the confining potentials of the point contacts are made sufficiently asymmetric which results in an asymmetric lateral spin-orbit coupling that leads to spin polarization in the presence of strong electron-electron interaction. Non-equilibrium Green´s function simulation results for a model device strongly support this analysis.
Keywords :
Green´s function methods; magnetic fields; quantum point contacts; spin polarised transport; asymmetric lateral spin-orbit coupling; ballistic conductance; electron-electron interaction; external magnetic field; nonequilibrium Green´s function; quantum point contacts; spin analyzer; spin coherence length; spontaneous spin polarization; temperature 4.2 K; Electric variables measurement; Electrons; Filters; Green´s function methods; Magnetic confinement; Magnetic field measurement; Magnetic fields; Optical polarization; Voltage; Wire;
Conference_Titel :
Nanotechnology, 2009. IEEE-NANO 2009. 9th IEEE Conference on
Conference_Location :
Genoa
Print_ISBN :
978-1-4244-4832-6
Electronic_ISBN :
1944-9399
