Tunable All Electric Spin Polarizer Using A Quantum Point Contact With Two Pairs of In-Plane Side Gates
Abstract
We report the first experimental investigation of a device consisting of a quantum point contact (QPC) with four gates - two in-plane side gates in series. The first set of gates (nearest the source contact) is asymmetrically biased to create spin polarization in the channel of the QPC. A symmetric bias is then applied on the second set of side gates (nearest the drain) and varied to tune the location of a conductance anomaly near 0.5 (x2e2/h). The experimental results compare well with simulations of the four-gate QPC devices using a Non-Equilibrium Green's Function formalism. The device is shown to be a tunable all-electric spin polarizer. The range of common-mode bias on the first set of gates over which maximum spin polarization can be achieved is much broader for the four-gate structure compared with the case of a QPC with a single pair of in-plane side gates.
This work is supported by NSF under Award 1028483.- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2013
- Bibcode:
- 2013APS..MARN18012B