  The giant optical nonlocality near the Dirac point in lossless
metal-dielectric multilayer metamaterials is revealed and investigated through
the analysis of the band structure of the multilayer stack in the
three-dimensional omega-k space, according to the transfer-matrix method with
the optical nonlocal effect. The position of the Dirac point is analytically
located in the omega-k space. It is revealed that the emergence of the Dirac
point is due to the degeneracy of the symmetric and the asymmetric eigenmodes
of the coupled surface plasmon polaritons. The optical nonlocality induced
epsilon-near-zero frequency shift for the multilayer stack compared to the
effective medium is studied. Furthermore, the giant optical nonlocality around
the Dirac point is explored with the iso-frequency contour analysis, while the
beam splitting phenomenon at the Dirac point due to the optical nonlocal effect
is also demonstrated.
