Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session F07: Fractional Quantum Hall 2
11:15 AM–2:15 PM,
Tuesday, March 6, 2018
LACC Room: 153B
Sponsoring Unit: DCMP
Chair: Jeanie Lau, Ohio State University
Abstract: F07.00008 : Wide AlAs quantum wells with > 106 cm2V-1s-1 mobility*
12:39 PM–12:51 PM
Modulation-doped Al0.33Ga0.67As/AlAs/Al0.33Ga0.67As quantum wells with electron densities of 1.4, 2.2, and 3.3 x 1011 cm-2 were grown with well widths ranging from 11 nm to 50 nm. In these samples electrons occupy in-plane valleys with large and anisotropic effective masses (longitudinal and transverse effective masses are 1.0 and 0.21, in units of free electron mass). We find that the optimized well width varies according to sample density, most likely because of scattering contributions from the second sub-band. Our highest quality samples show exceptional mobility values as high as 2.4 x 106 cm2V-1s-1 at the density of 2.2 x 1011 cm-2, and we observe high order fractional quantum Hall states up to 8/15 in samples with 1.4 x 1011 cm-2 density. These advances clearly demonstrate that 2D electrons in AlAs now have quality comparable to modern GaAs, highlighting the system as an excellent candidate to study electron-electron interactions in an anisotropic, multi-valley environment.
*Work supported by the NSF (Grants DMR 1305691, DMR 1709076, ECCS 1508925, and MRSEC DMR 1420541), the DOE Basic Energy Sciences (Grant DE-FG02-00-ER45841), and the Gordon and Betty Moore Foundation (Grant GBMF4420).
The American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics.
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