MAGNETORESISTANCE OVER THE INTERMEDIATE LOCALIZATION REGIME IN GAAS ALXGA1-XAS QUANTUM WIRES/

A low-temperature (0.04 < T < 2 K), low-magnetic-field (B < 300 mT) tr ansport study of GaAs/AlxGa1-xAs wires shows giant negative magnetores istance, induced by reducing T, confirming one-dimensional localizatio n. The magnetoresistance is described by R(TB) = R0 + R1(T) + R2(T)/[1 + (B/DELTAB)2], and the T-dependent terms exhibit power laws, R1(T) a pproximately T-1/2 and R2(T) approximately T-1, characteristic of elec tron interaction and quantum interference effects, respectively. At th e lowest T, R1(T) and R2(T) saturate to a T-independent value indicati ng that the effective wire length may not be increased further by redu cing T, below T(c). The results demonstrate a temperature-induced dime nsional crossover, from D = 1 to 0, in GaAs/AlxGa1-xAs quantum wires.