        EXPECTED_MAGNET = " the recent experiment in the surface states of the topological insulator bi@xmath0se @xmath1, however, reported that a large positive magnetoresistance becomes very linear in perpendicular magnetic field even in an opposite situation where the carrier sheet density is high that all electrons occupy more than one landau levels. \n it is striking that this observation is in conflict with abrikosov s model and also with the classical parish - littlewood model. "
