Giant Spatial Redistribution of Electrons in a Wide Quantum Well Induced by Quantizing Magnetic Field

• Published in: JETP letters 2023-06, Vol.117 (12), p.938-944
• Main Authors: Dorozhkin, S. I., Kapustin, A. A., Fedorov, I. B., Umansky, V., Smet, J. H.
• Format: Article
• Language: English
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Compressibility; Condensed Matter; Electron distribution; Electrons; Field effect transistors; Gallium arsenide; Heterostructures; Magnetic fields; Molecular; Monolayers; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum Hall effect; Quantum Information Technology; Quantum wells; Semiconductor devices; Solid State Physics; Spintronics
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364023601367

In samples of field-effect transistors based on GaAs/AlGaAs heterostructures with an electron system in a single 50-nm-wide GaAs quantum well, a transition stimulated by a quantizing magnetic field has been detected from a bilayer state of the system in zero magnetic field to a single-layer state when only the lowest Landau level is filled. In contrast to the results for the 60-nm-wide quantum well obtained in [S. I. Dorozhkin, A. A. Kapustin, I. V. Fedorov, V. Umansky, and J. H. Smet, Phys. Rev. V 102 , 235307 (2020)], the single-layer state is observed not only in incompressible quantum Hall effect states of the electron system at filling factors of 1 and 2, but also in compressible states between these filling factors. The spatial location of the single-layer system in the quantum well has been established; it appears to be independent of the electron distribution over the layers in a low magnetic field. A possible qualitative explanation for this observation has been proposed. The detected transition is supposedly due to the negative compressibility of two-dimensional electron systems caused by exchange-correlation contributions to the electron−electron interaction.