Effect of Quantum Hall Edge Strips on Valley Splitting in Silicon Quantum Wells

Brian Paquelet Wuetz, Merritt P. Losert, Alberto Tosato, Mario Lodari, Peter L. Bavdaz, Lucas Stehouwer, Amir Sammak, Menno Veldhorst, Giordano Scappucci*, More Authors

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

12 Citations (Scopus)
150 Downloads (Pure)

Abstract

We determine the energy splitting of the conduction-band valleys in two-dimensional electrons confined to low-disorder Si quantum wells. We probe the valley splitting dependence on both perpendicular magnetic field B and Hall density by performing activation energy measurements in the quantum Hall regime over a large range of filling factors. The mobility gap of the valley-split levels increases linearly with B and is strikingly independent of Hall density. The data are consistent with a transport model in which valley splitting depends on the incremental changes in density eB/h across quantum Hall edge strips, rather than the bulk density. Based on these results, we estimate that the valley splitting increases with density at a rate of 116 μeV/1011 cm-2, which is consistent with theoretical predictions for near-perfect quantum well top interfaces.

Original languageEnglish
Article number186801
Number of pages5
JournalPhysical Review Letters
Volume125
Issue number18
DOIs
Publication statusPublished - 2020

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