  The Klein paradox, first introduced in relation to chiral tunneling, is also
manifested in the study of bound-states in single-layer graphene with a 1D
square-well potential. We derive analytic (and numerical) solutions for
bound-state wavefunctions, in the absence and in the presence of an external
transverse magnetic field, and calculate the corresponding dipole transition
rates, which can be probed by photon absorption experiments. The role of parity
and time-reversal symmetries is briefly discussed. Our results are also
relevant for the physics of bound states of light in periodic optical waveguide
structures.
