Experimental verification of electrostatic boundary conditions in gate-patterned quantum devices
| Autor: | C. J. B. Ford, David A. Ritchie, John P. Griffiths, Tzu-Kan Hsiao, Girish Rughoobur, Ian Farrer, Yousun Chung, Andrew J. Flewitt, Ateeq Nasir, Hangtian Hou |
|---|---|
| Přispěvatelé: | Hou, H [0000-0003-4950-8190], Rughoobur, G [0000-0002-1693-4532], Flewitt, AJ [0000-0003-4204-4960], Apollo - University of Cambridge Repository |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Acoustics and Ultrasonics FOS: Physical sciences 02 engineering and technology Electron Dielectric Applied Physics (physics.app-ph) 01 natural sciences surface acoustic wave Overlayer Condensed Matter::Materials Science Condensed Matter::Superconductivity 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Boundary value problem 010306 general physics Quantum patterned quantum device Condensed Matter - Mesoscale and Nanoscale Physics business.industry Doping Surface acoustic wave Heterojunction Physics - Applied Physics 021001 nanoscience & nanotechnology Condensed Matter Physics boundary condition Surfaces Coatings and Films Electronic Optical and Magnetic Materials Optoelectronics 0210 nano-technology business |
| ISSN: | 0022-3727 |
| DOI: | 10.48550/arxiv.1806.09143 |
| Popis: | In a model of a gate-patterned quantum device it is important to choose the correct electrostatic boundary conditions (BCs) in order to match experiment. In this study, we model gated-patterned devices in doped and undoped GaAs heterostructures for a variety of BCs. The best match is obtained for an unconstrained surface between the gates, with a dielectric region above it and a frozen layer of surface charge, together with a very deep back boundary. Experimentally, we find a 0.2V offset in pinch-off characteristics of one-dimensional channels in a doped heterostructure before and after etching off a ZnO overlayer, as predicted by the model. Also, we observe a clear quantised current driven by a surface acoustic wave through a lateral induced n-i-n junction in an undoped heterostructure. In the model, the ability to pump electrons in this type of device is highly sensitive to the back BC. Using the improved boundary conditions, it is straightforward to model quantum devices quite accurately using standard software. Comment: 8 pages, 3 figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|