Engineering Flat Bands in InAs/GaSb Quad-layer Quantum Well Structures
ORAL
Abstract
Previous studies have shown that adjusting the relative thickness of InAs/GaSb double quantum wells (QWs) can transform the system from a semiconductor to a semimetal and create a dispersionless conduction band due to strong electron-hole wavefunction mixing. In our studies using k•p band structure calculations, we explore the potential to engineer flat bands in InAs/GaSb quad-layer QW materials. Using realistic band parameters and considering strain effects, our calculations show that nearly dispersionless bands can occur in specific parameter space windows. We investigate the validity of these predictions experimentally by probing the band structures of quad-layer QWs grown via molecular-beam epitaxy with magneto-infrared spectroscopy and magneto-transport. The Landau level transitions observed in this experiment can be directly compared to the optical conductivity calculated using the eight-band k•p model.
*This work is supported by the SNL, which is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. The infrared measurement is supported by the DOE through DE-FG02-07ER46451. The NHMFL is supported by the NSF through DMR-1644779 and the State of Florida. This work at GT is supported in part by the Institute for Electronics and Nanotechnology.
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Presenters
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Wei-Chen Wang
- Georgia Institute of Technology