Abstract: The present invention is achieved by layering a dielectric slab between a ground plane and a two dimensional quasi quantum well heterostructure and by switching between an unbiased state and a negative potential which is established between the quantum well heterostructure and the ground plane. In the unbiased state, the device supports wave propagation in the dielectric with a phase velocity similar to that of a wave propagating in a parallel plate waveguide. Upon application of the bias voltage, that is establishing a negative potential difference between contacts based on either side of the quantum well heterostructure, the conductivity of the quantum well decreases. Therefore, as the carrier wave propagates the wave interacts with a boundary similar to that of a dielectric-air interface. This new boundary condition, in turn, produces a faster phase velocity. Hence, toggling the bias modulates the quantum well conductivity which changes the phase velocity of the carrier wave.

Abstract: Methods of manufacturing rings, cylinders, hemispheres and spheres having a elatively strong central working field. The manufacture of complex magnetic structures is greatly simplified by a method of cutting wedge shaped portions radially into sections, rotating the bonded sections about a radial axis prior to magnetization, magnetizing the sections in a uniform magnetic field, rotating the magnetic sections into their original positions thereby forming the resulting desired permanent magnet structure. In another embodiment, another method of making a hemispherical or spherical magnet structure using rings ground into wedge shaped portions and reassembled is disclosed. In another embodiment, a method of manufacturing a cylindrical quadrupole is disclosed whereby sections of a magic ring are removed and collapsed to form half a cylinder and combined with an analogously collapsed magic ring forming a second half cylinder and combined to form a quadrupole.