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This article is cited in 2 scientific papers (total in 2 papers)
CONDENSED MATTER
Band flattening and Landau level merging in strongly-correlated two-dimensional electron systems
V. T. Dolgopolova, M. Yu. Melnikova, A. A. Shashkina, S. V. Kravchenkob a Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Moscow region, 142432 Russia
b Physics Department, Northeastern University, Boston, Massachusetts, 02115 USA
Abstract:
We review recent experimental results indicating the band flattening and Landau level merging at the chemical potential in strongly-correlated two-dimensional (2D) electron systems. In ultra-clean, strongly interacting 2D electron system in SiGe/Si/SiGe quantum wells, the effective electron mass at the Fermi level increases monotonically in the entire range of electron densities, while the energy-averaged mass saturates at low densities. The qualitatively different behavior of the two masses reveals a precursor to the interaction-induced single-particle spectrum flattening at the chemical potential in this electron system, in which case the fermion “condensation” at the Fermi level occurs in a range of momenta, unlike the condensation of bosons. In strong magnetic fields, perpendicular to the 2D electron layer, a similar effect of different fillings of quantum levels at the chemical potential – -the merging of the spin- and valley-split Landau levels at the chemical potential — is observed in Si inversion layers and bilayer 2D electron system in GaAs. Indication of merging of the quantum levels of composite fermions with different valley indices is also reported in ultra-clean SiGe/Si/SiGe quantum wells.
Received: 27.04.2022 Revised: 10.06.2022 Accepted: 21.06.2022
Citation:
V. T. Dolgopolov, M. Yu. Melnikov, A. A. Shashkin, S. V. Kravchenko, “Band flattening and Landau level merging in strongly-correlated two-dimensional electron systems”, Pis'ma v Zh. Èksper. Teoret. Fiz., 116:3 (2022), 159–170; JETP Letters, 116:3 (2022), 156–166
Linking options:
https://www.mathnet.ru/eng/jetpl6725 https://www.mathnet.ru/eng/jetpl/v116/i3/p159
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