Das, P.P.Jones, A.Cahay, M.Kalita, S.Mal, S.S.Sterin, N.S.Yadunath, T.R.Advaitha, M.Herbert, S.T.2026-02-052017Journal of Applied Physics, 2017, 121, 8, pp. -218979https://doi.org/10.1063/1.4977110https://idr.nitk.ac.in/handle/123456789/25683The observation of a 0.5 × (2e2/h) conductance plateau in asymmetrically biased quantum point contacts (QPCs) with in-plane side gates (SGs) has been attributed to the onset of spin-polarized current through these structures. For InAs QPCs with the same width but a longer channel length, there is roughly a fourfold increase in the range of common sweep voltage applied to the SGs over which the 0.5 × (2e2/h) plateau is observed when the QPC aspect ratio (ratio of length over the width of the narrow portion of the structure) is increased by a factor 3. Non-equilibrium Green's function simulations indicate that the increase in the size of the 0.5 × (2e2/h) plateau is due to an increased importance, over a larger range of common sweep voltage, of the effects of electron-electron interactions in QPC devices with a larger aspect ratio. The use of asymmetrically biased QPCs with in-plane SGs and large aspect ratio could therefore pave the way to build robust spin injectors and detectors for the successful implementation of spin field effect transistors. © 2017 Author(s).Electron-electron interactionsField effect transistorsPoint contactsQuantum chemistryChannel lengthIn-plane side gatesLarge aspect ratioNon-equilibrium Green's functionQuantum point contactSpin field-effect transistorsSpin polarized currentsAspect ratio