Fig. 8: Wave functions of electrons with the Peierls distortion.
a The wave function in the unit cell (dimer) can be expressed in terms of bonding and anti-bonding molecular orbits. The white and black circles express the sign of the wave functions. The dots express the positions of nodes in the wave function. b The symmetric (ψs) and antisymmetric (ψa) wave functions can be expressed in terms of bonding and anti-bonding as well. c The sign of ψa is inverted by the parity operation (k → −k), while that of ψs is unchanged. It is thus naively expected that ψa is strongly disturbed around the boundary by the normal reflection. d Illustration of the parity operation in the cyclotron edge. In the antisymmetric case, there is a π phase shift between incoming and reflected cyclotron orbits interrupted by the boundary.
