Yang–Lee circle theorem for an ideal pseudospin-1/2 Bose gas in an arbitrary external potential and in an external magnetic field

Yang–Lee circle theorem was extended to an ideal homogeneous pseudospin-1/2 Bose gas in an external magnetic field [X.Z. Wang, Phys. Rev. E 63 (2001) 046103]. In this paper, the theorem is extended to the case with an arbitrary external potential. The densities of zeros for several cases are determined. It is found that the critical exponents of the Yang–Lee edge singularities are the mean-field values, , independent of external potentials and spatial dimensions.