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Wuetz BP, Losert MP, Tosato A, Lodari M, Bavdaz PL, Stehouwer L, Amin P, Clarke JS, Coppersmith SN, Sammak A, Veldhorst M, Friesen M, Scappucci G. Effect of Quantum Hall Edge Strips on Valley Splitting in Silicon Quantum Wells. Phys Rev Lett 2020; 125:186801. [PMID: 33196242 DOI: 10.1103/physrevlett.125.186801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
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/10^{11} cm^{-2}, which is consistent with theoretical predictions for near-perfect quantum well top interfaces.
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Affiliation(s)
- Brian Paquelet Wuetz
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | | | - Alberto Tosato
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Mario Lodari
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Peter L Bavdaz
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Lucas Stehouwer
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Payam Amin
- Components Research, Intel Corporation, 2501 NW 229th Ave, Hillsboro, Oregon 97124, USA
| | - James S Clarke
- Components Research, Intel Corporation, 2501 NW 229th Ave, Hillsboro, Oregon 97124, USA
| | | | - Amir Sammak
- QuTech and Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK Delft, Netherlands
| | - Menno Veldhorst
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
| | - Mark Friesen
- University of Wisconsin-Madison, Madison, Wisconsin 53706 USA
| | - Giordano Scappucci
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, Netherlands
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