From particle in a box to PT -symmetric systems via isospectral deformation

A family of PT -symmetric complex potentials is obtained, which is isospectral to free particle in an infinite complex box in one dimension (1-D). These are generalizations to the cosec2 (x) potential, isospectral to particle in a real infinite box. In the complex plane, the infinite box is extended parallel to the real axis having a real width, which is found to be an integral multiple of a constant quantum factor, arising due to boundary conditions necessary for maintaining the PT -symmetry of the superpartner. As the spectra of the particle in a box is still real, it necessarily picks out the unbroken PT -sector of its superpartner, thereby invoking a close relation between PT -symmetry and SUSY for this case. As expected, the broken PT -sector has no isospectrality with any real system.
8 pages, 2 figures, figures have been updated and PACS numbers have been added, text have been updated with enhanced contents and references