title: Extreme sensitivity of the spin-splitting and 0.7 anomaly to confining potential in one-dimensional nanoelectronic devices.
abstract: Quantum point contacts (QPCs) have shown promise as nanoscale spin-selective components for spintronic applications and are of fundamental interest in the study of electron many-body effects such as the 0.7 × 2e(2)/h anomaly. We report on the dependence of the 1D Landé g-factor g and 0.7 anomaly on electron density and confinement in QPCs with two different top-gate architectures. We obtain g values up to 2.8 for the lowest 1D subband, significantly exceeding previous in-plane g-factor values in AlGaAs/GaAs QPCs and approaching that in InGaAs/InP QPCs. We show that g is highly sensitive to confinement potential, particularly for the lowest 1D subband. This suggests careful management of the QPC's confinement potential may enable the high g desirable for spintronic applications without resorting to narrow-gap materials such as InAs or InSb. The 0.7 anomaly and zero-bias peak are also highly sensitive to confining potential, explaining the conflicting density dependencies of the 0.7 anomaly in the literature.
authors: School of Physics, University of New South Wales, Sydney NSW 2052, Australia. amburke@unsw.edu.au
authors: A M
authors: AM
authors: Burke
authors: O
authors: O
authors: Klochan
authors: I
authors: I
authors: Farrer
authors: D A
authors: DA
authors: Ritchie
authors: A R
authors: AR
authors: Hamilton
authors: A P
authors: AP
authors: Micolich
mesh_terms: D004579:Electron Transport; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008839:Microelectrodes; D036103:Nanotechnology / Q000295:instrumentation*; D012666:Semiconductors