Spectroscopy of coupled one-dimensional subbands

A quantum point contact with one-dimensional subbands described by two quan tum numbers has been realized by laterally confining a quasi two-dimensiona l electron gas of a AlGaAs parabolic quantum well by split-gate electrodes. We measured quantized conductance reflecting the 1D subband structure in t he constriction, By applying magnetic fields, the confinement changes and w e observe crossings and anticrossings of magneto-electrical 1D subbands, de pending on the orientation of the magnetic field.