摘要
Since the discovery of Majorana fermions in condensed matter systems, new quasiparticle predictions of novel fermions have been predicted in solid state systems which exhibit three, six or eight fold degenerate band crossings protected by crystal symmetty in presence of spin orbit coupling and time reversal symmetry [1]. The nontrivial topology in condensed matter systems results from the crossings of conduction and valence bands. And the cases of g = 3, 6, and 8 are of particularly interesting as they can only be found in condensed matter systems, having no high energy analogues as constrained by Poincare symmetry [2].
