PLASMONS ON WIDE EPITAXIALLY-GROWN QUANTUM-WELLS

Quantum wells can now be grown by molecular beam epitaxy in the Ga1-xA lxAs system with almost any desired electron confinement potential V(z ) in the growth or z direction. The wells can be filled by remote dopi ng, giving finely controllable high-mobility electron gases with a dim ensionality between two and three. Grating coupler techniques permit o bservation at finite surface wavenumber of the infrared plasmon modes of these structures. This provides in principle a window onto fundamen tal and applicable many-electron physics. Of special interest are the 'pseudo-jellium' properties of parabolic and parabolic-linear wells, w hich are discussed in detail here. A theorem applicable to more genera l wells is also introduced.