Microwave radiation absorption by 2D-electrons in the type II composite InAs/GaSb/AlSb quantum wells in a magnetic field

18th International Conference PhysicA.SPb

Kochman, I.V.^1 ; Veinger, A.I.^1 ; Mikhailova, M.P.^1 ; Semenikhin, P.V.^1 ; Kalinina, K.V.^1 ; Parfeniev, R.V.^1 ; Berezovetz, V.A.^1 ; Hospodková, A.^2 ; Pangrác, J.^2 ; Hulicius, E.^2

Ioffe Physical-Technical Institute, Politkhnicheskaya, 26, St.-Petersburg

194021, Russia^1

Institute of Physics CAS CR, V.v.i., Cukrovarnická 10, Prague

162 00, Czech Republic^2

关键词: Angular dependence;    Composite quantum well;    Electron paramagnetic resonance spectroscopy;    Inversion asymmetry;    Microwave absorption;    Radiation absorption;    Shubnikov-de-haas oscillations;    Spline interpolation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/769/1/012075/pdf
DOI  :  10.1088/1742-6596/769/1/012075

来源: IOP

【 摘 要 】

Strong Shubnikov - de Haas (SdH) oscillations were observed in the derivative of microwave absorption (f = 10 GHz) in the InAs/GaSb/AlSb composite quantum wells (CQWs) using electron-paramagnetic-resonance spectroscopy at low temperatures (2.7-20 K) and in the magnetic field up to 14 kOe. CQWs were grown on the n-GaSb:Te(100) and n-InAs:Mn(100) substrates with various width of QWs by MOVPE. Predominance contribution of the bulk n- GaSb substrate in SdH oscillations was manifested. Two frequencies of the SdH oscillations were found from Fourier analysis, which is connected to warping of the Fermi surface of GaSb. Unusual angular indicatrix was observed in dependence on orientation of the samples in the magnetic field. Obtained results can be explained by inversion asymmetry, which is a feature of the substances with lack of inversion centres. For CQWs grown on n-InAs:Mn (ns= 1.1 × 1017cm-3) substrate, only several SdH oscillations with higher period were observed. Taking into account isotropic Fermi surface of bulk InAs, we succeeded to extract a contribution of the 2D carriers of InAs QW ∼ H⊥, where H⊥= HconstcosΘ, from bulk substrate oscillations using special spline interpolation from angular dependence of SdH oscillatory amplitudes in the angle range 0-90°. 2D electron concentration in the InAs QW ns≈ 1 - 3 × 1011cm-2was evaluated from oscillatory period.