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High-quality C-doped p-type AlGaAs heterostructures with mobilities exceeding 150 000 cm$^2$/Vs are investigated by low-temperature magnetotransport experiments. We find features of the fractional quantum Hall effect as well as a highly resolved Shubnikov-de Haas oscillations at low magnetic fields. This allows us to determine the densities, effective masses and mobilities of the holes populating the spin-split subbands arising from the lack of inversion symmetry in these structures.
The two-terminal magneto-conductance of a hole gas in C-doped AlGaAs/GaAs heterostructures with ohmic contacts consisting of alloyed In/Zn/Au displays a pronounced hysteresis of the conductance around zero magnetic field. The hysteresis disappears ab
We use a van-der-Waals pickup technique to fabricate different heterostructures containing WSe$_2$(WS$_2$) and graphene. The heterostructures were structured by plasma etching, contacted by one-dimensional edge contacts and a topgate was deposited. F
We report on magnetotransport measurements in two MBE-grown GaAs/AlGaAs superlattices formed by wide and narrow quantum wells and thin Si-doped barriers subject to tilted magnetic fields. It has been shown that illumination of the strongly coupled su
We demonstrate a method of making a very shallow, gateable, undoped 2-dimensional electron gas. We have developed a method of making very low resistivity contacts to these structures and systematically studied the evolution of the mobility as a funct
This paper reports on the observation and analysis of magnetotransport phenomena in the nonlinear differential resistance $r_{xx}=dV_{xx}/dI$ of high-mobility InGaAs/InP and GaAs/AlGaAs Hall bar samples driven by direct current, $Idc$. Specifically,