Energy band structure due to a complex, periodic, PT-invariant potential

Using a complex PT-invariant, periodic potential of Kronig-Penny type, we show the occurrence of the usual energy band structure. Occurrence of a new type of band structure is also revealed wherein the Brillouin zone boundaries (BZBs: kL = 0, pi) may not be reached and along with band gaps rounded double bands may occur near the BZBs. (C) 2001 Published by Elsevier Science B.V.