  Harnessing artificial optical magnetism requires rather complex two- and
three-dimensional structures, examples include split-ring and fishnet
metamaterials and nanoparticles with non-trivial magnetic properties. By
contrast, dielectric properties can be tailored even in planar and
pattern-free, one-dimensional (1D) arrangements, for example metal/dielectric
multilayer metamaterials. These systems are extensively investigated due to
their hyperbolic and plasmonic response, which, however, is considered to be
limited to TM polarization, based on the general consensus that they do not
possess interesting magnetic properties. In this work, we tackle these two
seemingly unrelated issues simultaneously, by proposing conceptually and
demonstrating experimentally a mechanism for artificial magnetism in planar, 1D
metamaterials. We show experimentally that the magnetic response of
metal/high-index dielectric hyperbolic metamaterials can be anisotropic,
leading to frequency regimes of magnetic hyperbolic dispersion. We investigate
the implications of our results for TE polarization and show that such systems
can support TE interface-bound states, analogous to their TM counterparts,
surface plasmon polaritons. Our results simplify the structural complexity for
tailoring artificial magnetism in lithography-free systems and generalize the
concept of plasmonic and hyperbolic properties to encompass both TE and TM
polarizations at optical frequencies.
