Surface States of Bi₂Se₃ Nanowires in the Presence of Perpendicular Magnetic Fields

We study the surface states of Bi₂Se₃ nanowires (NWs) in the presence of perpendicular magnetic fields. It is found that the minigap of Bi₂Se₃, arising from the quantized surface states around the circumference of NWs can be closed by perpendicular magnetic fields. With increasing magnetic fields, the Landau levels and edge states appear and localize at the center and edge of NWs, respectively. More interestingly, magnetic fields split the electron surface subbands with opposite tangential momenta, leading to specific edge states with low group velocity.