Suppression of compressible edge channels and spatial spin polarization in the integer quantum Hall regime

W e perform system atic num ericalstudies ofthe structure ofspin-resolved com pressible strips in split-gate quantum wires taking into account the exchange and correlation interactions within the density functionaltheory in thelocalspin-density approxim ation.W e(cid:12)nd thatforrealisticparam e-tersofthe wire theexchange interaction can com pletely suppressthe form ation ofthecom pressible strips.A sthedepletion length orm agnetic(cid:12)eld areincreased,thecom pressiblestripsstartsto form (cid:12)rstforthespin-down and then forspin-up edgechannels.W edem onstratethatthewidthsofthese stripsplusthe spatialseparation between them caused by theexchange interaction are equalto the width ofthe com pressible strip calculated in the H artree approxim ation for spinless electrons. W e also discussthe e(cid:11)ectofelectron density on the suppression ofthe com pressible stripsin quantum wires.