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


Sarcan F., Nutku F., Donmez Ö., Kuruoglu F., Mutlu S., Erol A., ...More

JOURNAL OF PHYSICS D-APPLIED PHYSICS, vol.48, no.30, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 48 Issue: 30
  • Publication Date: 2015
  • Doi Number: 10.1088/0022-3727/48/30/305108
  • Journal Name: JOURNAL OF PHYSICS D-APPLIED PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: GaInNAs, dilute nitride, quantum Hall effect, Shubnikov de Haas (SdH) oscillations, weak localization, weak antilocalization, negative magnetoresistance, WEAK ANTILOCALIZATION, TEMPERATURE-DEPENDENCE, ELECTRONIC-STRUCTURE, DILUTE NITRIDE, BAND-GAP, HALL, LOCALIZATION, MAGNETORESISTANCE, MAGNETOTRANSPORT, CONDUCTIVITY
  • Istanbul University Affiliated: Yes

Abstract

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 rho(xx) and quantum Hall effect (QHE) plateaus in rho(xy) 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 rho(xy) 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.