Obiettivo
High field magnetotransport and magnetooptical studies of semiconductor have been carried out on 1-dimensional subbands in multiple wires on silicon metal oxide semiconductor field effect transistors (MOSFET), on pinched off 1-dimensional channels in heterojunctions, on half-plateaus in heterojunctions, on quantum dots and on thermal transport in free standing gallium arsenide wires. High carrier density heterostructures have been studied in terms of electron relaxation times, for infrared magnetooptics and Fernii edge induced photoluminescence. High mobility induim antimonide-cadmium telluride heterojunctions have been investigated. An all plastic dilution refrigerator has been constructed for use in a 30 T hybrid system in high field experiments.
The collaborative project will combine the exceptional growth and nanofabrication facilities at the University of Cambridge, and the world-class magnetic field and optical facilities at the University of Nijmegen. Quantum wires, quantum dots, lateral superlattices and other small devices in which quantum size effects are important will be fabricated on high-mobility GaAs- (Ga, Al)As heterojunctions at the Cavendish Laboratory in Cambridge. These devices will be studied at the High Field Magnet Laboratory in Nijmegen, in order to characterise the size effects, reveal the roles of localisation and interference, and examine edge current effects. Information of the fractional and integer quantum Hall effects will also be obtained from the high-field experiments.