Magnetic quantum dot: a magnetic transmission barrier and resonator.
We study the ballistic edge-channel transport in quantum wires with a magnetic quantum dot, which is formed by two different magnetic fields B(*) and B0 inside and outside the dot, respectively. We find that the electron states located near the dot and the scattering of edge channels by the dot strongly depend on whether B(*) is parallel or antiparallel to B0. For parallel fields, two-terminal conductance as a function of channel energy is quantized except for resonances, while, for antiparallel fields, it is not quantized and all channels can be completely reflected in some energy ranges. All these features are attributed to the characteristic magnetic confinements caused by nonuniform fields.
Sim
H S
HS
Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701, Korea.
Ihm
G
G
Kim
N
N
Chang
K J
KJ