Capacitance of gated GaAs/ Al x Ga 1 − x As heterostructures subject to in-plane magnetic fields

Physical review. B, Condensed matter (Impact Factor: 3.66). 05/1995; 51(15):10181-10184. DOI: 10.1103/PhysRevB.51.10181
Source: PubMed


A detailed analysis of the capacitance of gated GaAs/AlxGa1-xAs heterostructures is presented. The nonlinear dependence of the capacitance on the gate voltage and in-plane magnetic field is discussed together with the capacitance quantum steps connected with a population of higher two-dimensional gas subbands. The results of full self-consistent numerical calculations are compared to recent experimental data.

Download full-text


Available from: Ludvik Smrcka
  • Source
    • "where L is the thickness of the AlGaAs-layer, i is the dielectric constant of the layer and K is a constant that takes into account fixed charges in the AlGaAs. Differentiating Eq.(12) with respect to n e , one obtain the total inverse magneto-capacitance per unit area C(B) at a given temperature T [28] [29] "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we present calculations on the density of states (DOS) and the magnetocapacitance of the 2DEG in a MODFET under two-dimensional (2D) weak periodic modulation in the presence of a perpendicular magnetic field. Adopting a Gaussian broadening of magnetic-field-dependent width, we present explicit and simple expressions for the DOS, valid for the relevant weak magnetic fields and modulation strengths. As the modulation strength in both directions increase, beating patterns of the magnetocapacitance oscillations are observed in the low-magnetic-field range (Weiss-oscillations regime) which are absent in the 1D weak modulation case.
    Full-text · Article · Apr 2007 · Microelectronics Journal
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is shown that capacitance spectroscopy can be used to investigate the spin polarization of two-dimensional electronic systems (2DESs). We employed this method to investigate the spin polarization of 2DESs in a GaAs/AlGaAs heterojunction for filling factors of the magneticquantization levels 0.28<ν<0.9. It is proved that in the presence of states of the fractional quantum Hall effect with ν f =1/3 and 2/3 the ground state of a 2DES with ν>2/3 is incompletely spin-polarized.
    No preview · Article · Jan 1997 · JETP Letters
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report on the effect of an in-plane magnetic field component on the magnetoresistance of the two-dimensional electron system (2DES) and capacitance between the 2DES and gate. The appearance of the ν=1/3 and ν=2/3 fractional-quantum-Hall-effect (FQHE) states has been observed to modify the effect at ν≳2/3. Our results imply the existence of the spin-reversed quasielectron excitations in the ν=2/3 FQHE. Charged excitations with large numbers of reversed spins (skyrmions) recently predicted for the ν=1/3 FQHE state have not been found.
    No preview · Article · Feb 1997 · Physical review. B, Condensed matter
Show more