EXCHANGE INTERACTION IN QUANTUM-WIRE SUBBANDS

The many-electron ground state is studied in a quantum wire with sever al populated spin and orbital subbands. The many-body effect is treate d in the lowest order. The phase diagram of the subband population is obtained as a function of magnetic field and the strength of the confi ning potential. If the magnetic field is small, there is a phase bound ary between spin-polarized states and partially spin-polarized states. Using these results, transport characteristics are calculated using L andauer's formula and a dip is predicted in the conductance plateau of 2e(2)/h.