Spin splitting of surface states in HgTe quantum wells

• Дата: 2019
• Автори: Dobretsova, A.A., Kvon, Z.D., Krishtopenko, S.S., Mikhailov, N.N., Dvoretsky, S.A.
• Формат: Стаття
• Мова: Russian
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2019
• Назва видання: Физика низких температур
• Теми: Спеціальний випуск. «XXII Уральська міжнародна зимова школа з фізики напівпровідників» (20–23 лютого, 2018)
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/175794
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Spin splitting of surface states in HgTe quantum wells / A.A. Dobretsova, Z.D. Kvon, S.S. Krishtopenko, N.N. Mikhailov, S.A. Dvoretsky // Физика низких температур. — 2019. — Т. 45, № 2. — С. 185-191. — Бібліогр.: 34 назв. — рос.

We report on beating appearance in Shubnikov–de Haas oscillations in conduction band of 18–22 nm HgTe quantum wells under applied top-gate voltage. Analysis of the beatings reveals two electron concentrations at the Fermi level arising due to Rashba-like spin splitting of the first conduction subband H₁. The difference ΔNs in two concentrations as a function of the gate voltage is qualitatively explained by a proposed toy electrostatic model involving the surface states localized at quantum well interfaces. Experimental values of ΔNs are also in a good quantitative agreement with self-consistent calculations of Poisson and Schrödinger equations with eightband k p⋅ Hamiltonian. Our results clearly demonstrate that the large spin splitting of the first conduction subband is caused by surface nature of H₁ states hybridized with the heavy-hole band.