Quantum oscillations and interference effects in strained n- and p-type modulation doped GaInNAs/GaAs quantum wells

• Published in: Journal of physics. D, Applied physics Vol. 48; no. 30; pp. 305108 - 9
• Main Authors: Sarcan, F, Nutku, F, Donmez, O, Kuruoglu, F, Mutlu, S, Erol, A, Yildirim, S, Arikan, M C
• Format: Journal Article
• Language: English
• Published: IOP Publishing 05.08.2015
• Subjects: dilute nitride; GaInNAs; Gallium arsenide; Gallium arsenides; Indication; Modulation; negative magnetoresistance; Oscillations; Quantum Hall effect; Quantum wells; Shubnikov de Haas (SdH) oscillations; Spin-orbit interactions; weak antilocalization; weak localization
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/48/30/305108

We have performed magnetoresistance measurements on n- and p-type modulation doped GaInNAs/GaAs quantum well (QW) structures in both the weak (B  < 0.08 T) and the high magnetic field (up to 18 T) at 75 mK and 6 K. We observe that the quantum oscillations in and quantum Hall effect (QHE) plateaus in are affected from the presence of the nitrogen in the III-V lattice. The enhancement of N-related scatterings and electron effective mass with increasing nitrogen causes lower electron mobility and higher two-dimensional (2D) electron density, leading to suppressed QHE plateaus in up to 7 T at 6 K. The Shubnikov de Haas (SdH) oscillations develop at lower magnetic fields for higher mobility samples at 6 K and the amplitude of SdH oscillations decreases with increasing nitrogen composition. The well-pronounced QHE plateaus are observed at 75 mK and at higher magnetic fields up to 18 T, for the p-type sample. For n-type samples, the observed anomalies in the characteristic of QHE is attributed the nitrogen-related disorders and overlapping of fluctuating Landau levels. The low magnetic field measurements at 75 mK reveal that the n-type samples exhibit weak antilocalization, whereas weak localization is observed for the p-type sample. The observation of weak antilocalization is an indication of strong electron spin-orbit interactions. The low field magnetoresistance traces are used to extract the spin coherence, phase coherence and elastic scattering times as well Rashba parameters and spin-splitting energy. The calculated Rashba parameters for nitrogen containing samples reveal that the nitrogen composition is a significant parameter to determine the degree of the spin-orbit interactions. Consequently, GaInNAs-based QW structures with various nitrogen compositions can be beneficial to adjust the spin-orbit coupling strength and may be used as a candidate for spintronics applications.