Quantum transport in GaInAs-AlInAs heterojunctions, and the influence of intersubband scattering

https://repository.ubn.ru.nl/bitstream/handle/2066/115596/115596.pdf

A study of intersubband scattering in GaAs/AlxGa1−xAs heterostructures by means of a parallel magnetic field

The “diamagnetic” Shubnikov-De Haas effect for multi-subband charge layers

The authors report cyclotron resonance measurements on GaInAs-AlInAs heterojunctions in which two electric subbands are occupied in magnetic fields with components both perpendicular and parallel to the interface. The parallel field component increases the energy separation of the two populated subbands and hence shifts the two sets of Landau levels due to the perpendicular field relative to one another. When the two sets of levels are coincident, a splitting is seen in the cyclotron resonance due to coupling of the degenerate states by the parallel magnetic field. The magnitude of the splitting is in agreement with a simple perturbation theory calculation.

Subband-Landau level coupling in a two-dimensional electron gas in tilted magnetic fields

The subband structure of electrons confined in a parabolic potential well, subjected to magnetic fields at arbitrary angles between the electric and magnetic field, is derived analytically. These theoretical results are used to analyze transport measurements on a thin layer of n-doped GaAs, confined between p layers under these conditions. Furthermore the results of numerical calculations of the Landau level structure in thin (periodicity < 120nm) GaAs-GaAlAs doping superlattices are presented for B parallel to the layers. These results show that cyclotron resonance can be observed as long the cyclotron energy is less than the subband width.

Combined Electric and Magnetic Field Effects in Semiconductor Heterostructures

The transconductance of an accumulation layer on $n$-type InAs is studied in a magnetic field $\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}$ parallel to the layer. Structures are observed, nonperiodic in $\frac{1}{H}$, corresponding to mixed electric and magnetic subbands. The effect promises a simple, sensitive method of probing the shape of the self-consistent potential in surface space-charge layers with multiply occupied subbands.

M. Nealon

Papers

Hybrid Quantum Oscillations in a Surface Space-Charge Layer

Determination of subband populations in tipped magnetic fields