Search for multiple-step integer quantum Hall transitions - art. no. 201313

Recent experiments in the integer quantum Hall regime seem to find direct t ransitions from quantum Hall states with Hall conductance sigma (xy)=ne(2)/ h with integer n> 1, to an insulating state in weak magnetic fields. We stu dy the issue of quantum Hall transitions with change in Hall conductance ne (2)/h with n> 1 using a variation of the tight-binding lattice model for no ninteracting electrons. Although such transitions do exist in our model for special tuning of parameters, they generically split, with the Hall conduc tance changing by e(2)/h at each transition. This suggests that a generic m ultiple step quantum Hall transition is incompatible with a noninteracting electron picture.