is described by the effective mass which is negative when the frequency approaches from above. Metamaterials exploiting the effect of the negative mass in the vicinity of the plasma frequency were reported. See also Electron wake List of plasma physics articles Plasmon Relativistic quantum chemistry Surface plasmon resonance Upper hybrid oscillation, in particular for a discussion of the modification to the mode at propagation angles oblique to the magnetic field Waves in plasmas References Further reading Waves in plasmas Plasma physics Plasmonics