63 research outputs found
Electron transport through antidot superlattices in heterostructures: new magnetoresistance resonances in lattices with large diameter antidots
In the present work we have investigated the transport properties in a number
of Si/SiGe samples with square antidot lattices of different periods. In
samples with lattice periods equal to 700 nm and 850 nm we have observed the
conventional low-field commensurability magnetoresistance peaks consistent with
the previous observations in GaAs/AlGaAs and Si/SiGe samples with antidot
lattices. In samples with a 600 nm lattice period a new series of
well-developed magnetoresistance oscillations has been found beyond the last
commensurability peak which are supposed to originate from periodic skipping
orbits encircling an antidot with a particular number of bounds.Comment: To appear in EuroPhys. Let
Unconventional Hall effect near charge neutrality point in a two-dimensional electron-hole system
The transport properties of the two-dimensional system in HgTe-based quantum
wells containing simultaneously electrons and holes of low densities are
examined. The Hall resistance, as a function of perpendicular magnetic field,
reveals an unconventional behavior, different from the classical N-shaped
dependence typical for bipolar systems with electron-hole asymmetry. The
quantum features of magnetotransport are explained by means of numerical
calculation of the Landau level spectrum based on the Kane Hamiltonian. The
origin of the quantum Hall plateau {\sigma}xy = 0 near the charge neutrality
point is attributed to special features of Landau quantization in our system.Comment: 8 pages, 7 figure
Quantum corrections to the conductivity and Hall coefficient of a 2D electron gas in a dirty AlGaAs/GaAs/AlGaAs quantum well: transition from diffusive to ballistic regime
We report an experimental study of the quantum corrections to the
longitudinal conductivity and the Hall coefficient of a low mobility, high
density two-dimensional two-dimensional electron gas in a AlGaAs/GaAs/AlGaAs
quantum well in a wide temperature range (1.5 K - 110 K). This temperature
range covers both the diffusive and the ballistic interaction regimes for our
samples. It was therefore possible to study the crossover region for the
longitudinal conductivity and the Hall effect
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