| Autor: |
Hossain, Md. S., Ma, M. K., Rosales, K. A. Villegas, Chung, Y. J., Pfeiffer, L. N., West, K. W., Baldwin, K. W., Shayegan, M. |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
Phys. Rev. Lett. 127, 116601 (2021) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevLett.127.116601 |
| Popis: |
Memory or transistor devices based on electron's spin rather than its charge degree of freedom offer certain distinct advantages and comprise a cornerstone of spintronics. Recent years have witnessed the emergence of a new field, valleytronics, which seeks to exploit electron's valley index rather than its spin. An important component in this quest would be the ability to control the valley index in a convenient fashion. Here we show that the valley polarization can be switched from zero to one by a small reduction in density, simply tuned by a gate bias, in a two-dimensional electron system. This phenomenon arises fundamentally as a result of electron-electron interaction in an itinerant, dilute electron system. Essentially, the kinetic energy favors an equal distribution of electrons over the available valleys, whereas the interaction between electrons prefers single-valley occupancy below a critical density. The gate-bias-tuned transition we observe is accompanied by a sudden, two-fold change in sample resistance, making the phenomenon of interest for potential valleytronic transistor device applications. Our observation constitutes a quintessential demonstration of valleytronics in a very simple experiment. |
| Databáze: |
arXiv |
| Externí odkaz: |
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