Abstract: A detector for detecting electromagnetic radiation, especially for electromagnetic radiation in the GHz or THz range. The detector comprises a semiconductor structure having a 2D charge carrier layer or a quasi 2D charge carrier layer with an edge, at least first and second contacts to said charge carrier layer, said contacts being provided at said edge and being spaced apart by a distance, and a device for measuring at least one of the photocurrent between said first and second contacts, the photovoltage between said first and second contacts and the resistance between said first and second contacts. A device is provided for applying a magnetic field to said detector with a field component perpendicular to said charge carrier layer. An output signal of said measuring device provides information about at least one of the presence of electromagnetic radiation, the intensity of the incident electromagnetic radiation and the frequency of the incident electromagnetic radiation.

Abstract: A detector for detecting electromagnetic radiation, especially for electromagnetic radiation in the GHz or THz range. The detector comprises a semiconductor structure having a 2D charge carrier layer or a quasi 2D charge carrier layer with an edge, at least first and second contacts to said charge carrier layer, said contacts being provided at said edge and being spaced apart by a distance, and a device for measuring at least one of the photocurrent between said first and second contacts, the photovoltage between said first and second contacts and the resistance between said first and second contacts. A device is provided for applying a magnetic field to said detector with a field component perpendicular to said charge carrier layer. An output signal of said measuring device provides information about at least one of the presence of electromagnetic radiation, the intensity of the incident electromagnetic radiation and the frequency of the incident electromagnetic radiation.

Abstract: A Hall effect device has a thin Hall element (10) having at least one hole or window and is bounded accordingly by at least one inner edge (10a, 10b) and, where required, also by an outer edge. One preferred embodiment having no current-induced misalignment voltages has a first pair of current connections (A,B) at two opposed locations on the outer edge (10a); a second pair of current connections (1,2) at two opposed locations on the inner edge (10b); at least one first pair of Hall voltage connections (C,E) at two opposed locations on the outer edge (10a) between the current connections (A,B) of the first pair; and/or at least one second pair of Hall voltage connections (3,5) at two opposed locations on the inner edge (10b) between the current connections (1,2) of the second pair. The currents (I.sub.A,B, I.sub.1,2) applied to the current connections may be dimensioned so that no misalignment voltages caused by internal voltage drops result at the Hall voltage connections.

Abstract: A novel unipolar transistor device has been realized starting from two-dimensional electron systems (2DES) in modulation-doped AlGaAS/GaAs heterostructures. A 600 nm wide 1D channel is insulated laterally from 2DES regimes by 700 nm wide deep mesa etched trenches. The conductivity in the quasi-one-dimensional channel can be tuned via the in-plane lateral-field effect of the adjacent 2DES-gates where the vacuum (or air) in the etched trenches serves as the dielectric. Room temperature operation is demonstrated yielding a 161S transconductance corresponding to 160 mS/mm 2D transconductance.

Abstract: A semiconductor radiation detector with layer-wise construction and a contive region having a two-dimensional or quasi one-dimensional electron or hole gas is provided in which adiabatic transport in edge channels occurs at least regionally and in which at least two contacts are provided to this conductive region. The transport in the edge channels is disturbed by interaction with the electromagnetic radiation to be detected, i.e. an increase of the scattering rate between the edge channels is caused. This leads to a change of the resistance measurable between the contacts, with a means being provided for measuring the change of resistance to thereby detect the incident radiation.