  We have previously found experimental evidence for several quantum phenomena
in oxygen-ion implanted of hydrogenated graphite: ferromagnetism,
antiferromagnetism, paramagentism, triplet superconductivity, Andreev states,
Little-Parks oscillations, Lamb shift, Casimir effect, colossal
magnetoresistance, and topologically-protected flat-energy bands [1-6]. Triplet
superconductivity results in the formation of Josephson junctions, thus with
potential of being used for spintronics applications in the critical area of
quantum computing. In this paper, we are showing new experimental evidence for
the formation of two-dimensional (2D) spin waves in oxygen-ion enriched and in
hydrogenated highly oriented pyrolytic graphite. The temperature evolution of
the remanent magnetization Mrem(T) data confirms the formation of spin waves
that follow the 2D Heisenberg model with a weak uniaxial anisotropy. In
addition, the step-like features also found in the temperature dependence of
the electrical resistivity between insulating and metallic states suggest
several outstanding possibilities, such as a structural transition, triplet
superconductivity, and chiral properties.
