Smith, L.W., Al-Taie, H., Lesage, A.A.J. et al. (9 more authors) (2016) Effect of Split Gate Size on the Electrostatic Potential and 0.7 Anomaly within Quantum Wires on a Modulation-Doped GaAs/AlGaAs Heterostructure. Physical Review Applied, 5 (4).
Abstract
We study 95 split gates of different size on a single chip using a multiplexing technique. Each split gate defines a one-dimensional channel on a modulation-doped GaAs/AlGaAs heterostructure, through which the conductance is quantized. The yield of devices showing good quantization decreases rapidly as the length of the split gates increases. However, for the subset of devices showing good quantization, there is no correlation between the electrostatic length of the one-dimensional channel (estimated using a saddle-point model) and the gate length. The variation in electrostatic length and the one-dimensional subband spacing for devices of the same gate length exceeds the variation in the average values between devices of different lengths. There is a clear correlation between the curvature of the potential barrier in the transport direction and the strength of the "0.7 anomaly": the conductance value of the 0.7 anomaly reduces as the barrier curvature becomes shallower. These results highlight the key role of the electrostatic environment in one-dimensional systems. Even in devices with clean conductance plateaus, random fluctuations in the background potential are crucial in determining the potential landscape in the active device area such that nominally identical gate structures have different characteristics.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 American Physical Society. This is an author produced version of a paper subsequently published in Physical Review Applied. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 23 Jun 2016 08:44 |
Last Modified: | 23 Jun 2016 08:44 |
Published Version: | https://dx.doi.org/10.1103/PhysRevApplied.5.044015 |
Status: | Published |
Publisher: | American Physical Society |
Identification Number: | 10.1103/PhysRevApplied.5.044015 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:101296 |