Journal
NANOTECHNOLOGY
Volume 23, Issue 21, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0957-4484/23/21/215201
Keywords
-
Funding
- NSF [ECCS 0725404, 1028483]
- Div Of Electrical, Commun & Cyber Sys
- Directorate For Engineering [1028423] Funding Source: National Science Foundation
Ask authors/readers for more resources
We study of the appearance and evolution of several anomalous (i.e., G < G(0) = 2e(2)/h) conductance plateaus in an In0.52Al0.48As/InAs quantum point contact (QPC). This work was performed at T D 4.2 K as a function of the offset bias Delta V-G between the two in-plane gates of the QPC. The number and location of the anomalous conductance plateaus strongly depend on the polarity of the offset bias. The anomalous plateaus appear only over an intermediate range of offset bias of several volts. They are quite robust, being observed over a maximum range of nearly 1 V for the common sweep voltage applied to the two gates. These results are interpreted as evidence for the sensitivity of the QPC spin polarization to defects (surface roughness and impurity (dangling bond) scattering) generated during the etching process that forms the QPC side walls. This assertion is supported by non-equilibrium Green function simulations of the conductance of a single QPC in the presence of dangling bonds on its walls. Our simulations show that a spin conductance polarization alpha as high as 98% can be achieved despite the presence of dangling bonds. The maximum in alpha is not necessarily reached where the conductance of the channel is equal to 0.5G(0).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available