  We extend the study of fermionic particle-hole symmetric semi-Dirac
(alternatively, semi-Weyo) dispersion of quasiparticles, $\varepsilon_K = \pm
\sqrt{(k_x^2/2m)^2 + (vk_y)^2)} = \pm \varepsilon_0 \sqrt{K_x^4 + K_y^2}$ in
dimensionless units, discovered computationally in oxide heterostructures by
Pardo and collaborators. This unique system a highly anisotropic sister phase
of both (symmetric) graphene and what has become known as a Weyl semimetal,
with $<v_y^2>^{1/2} \approx v$ independent of energy, and $<v_x^2>^{1/2}
\propto m^{-1/2}\sqrt{\varepsilon}$ being very strongly dependent on energy
($\varepsilon$) and depending only on the effective mass $m$. Each of these
systems is distinguished by bands touching (alternatively, crossing) at a point
Fermi surface, with one consequence being that for this semi-Dirac system the
ratio $|\chi_{orb}/\chi_{sp}|$ of orbital to spin susceptibilities diverges at
low doping. We extend the study of the low-energy behavior of the semi-Dirac
system, finding the plasmon frequency to be highly anisotropic while the Hall
coefficient scales with carrier density in the usual manner. The Faraday
rotation behavior is also reported. For Klein tunneling for normal incidence on
an arbitrarily oriented barrier, the kinetic energy mixes both linear
(massless) and quadratic (massive) contributions depending on orientation.
Analogous to graphene, perfect transmission occurs under resonant conditions,
except for the specific orientation that eliminates massless dispersion.
Comparisons of the semi-Dirac system are made throughout with both other types
of point Fermi surface systems.
