  Optical systems with gain and loss that respect Parity-Time (PT) symmetry can
have real eigenvalues despite their non-Hermitian character. Chiral systems
impose circularly polarized waves which do not preserve their handedness under
the combined space- and time- reversal operations and, as a result, seem to be
incompatible with systems possessing PT symmetry. Nevertheless, in this work we
show that in certain configurations, PT symmetric permittivity, permeability
and chirality is possible; in addition, real eigenvalues are maintained even if
the chirality goes well beyond PT symmetry. By obtaining all three constitutive
parameters in realistic chiral metamaterials through simulations and retrieval,
we show that the chirality can be tailored independently of permittivity and
permeability; thus, in such systems, a wide control of new optical properties
including advanced polarization control is achieved.
