|Title:||Density dependence of the excitation gaps in an undoped Si/SiGe double-quantum-well heterostructure||Authors:||Chen D
|Keywords:||Quantum chemistry;Quantum theory;Silicon;Temperature;Asymmetric double quantum wells;Bottom gate;Density dependence;Double quantum well heterostructures;Excitation gaps;Lows-temperatures;Magneto-transport measurement;Measurements of;Si/SiGe;Top gate;Semiconductor quantum wells||Issue Date:||2021||Journal Volume:||119||Journal Issue:||22||Source:||Applied Physics Letters||Abstract:||
We report low-temperature magneto-transport measurements of an undoped Si/SiGe asymmetric double quantum well heterostructure. The density in both layers is tuned independently utilizing top and bottom gates, allowing the investigation of quantum wells at both imbalanced and matched densities. Integer quantum Hall states at total filling factor ν T = 1 and ν T = 2 are observed in both density regimes, and the evolution of their excitation gaps is reported as a function of the density. The ν T = 1 gap evolution departs from the behavior generally observed for valley splitting in the single layer regime. Furthermore, by comparing the ν T = 2 gap to the single particle tunneling energy, Δ SAS, obtained from Schr?dinger-Poisson (SP) simulations, evidence for the onset of spontaneous interlayer coherence is observed for a relative filling fraction imbalance smaller than ? 50 %. ? 2021 Author(s).
|Appears in Collections:||電機工程學系|
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