The opening of One Hundred Years of Solitude is fantastic – “The world was so recent that many things lacked names, and in order to indicate them it was necessary to point”. Another interesting story about names is that in Journey to the West, the Silver Horned King has a powerful man-eating weapon called Purple Gold Red Gourd (strange translation taken from wikipedia). He calls someone’s name and if one replies the gourd will suck and digest that guy.
The story of names I going to talk here is about physics. A lot of new concepts have been brought out in the condensed matter physics. Some have names that can be easily understood. The composite fermion in the fractional quantum Hall physics, for example, is the “composite” of an electron and an even number of magnetic flux quanta. Some concepts have confusing names. The quantum anomalous Hall effect is a quantum version (quantized conductance) of the anomalous Hall effect. However, there is also the anomalous quantum Hall effect, which is an informal name describing anomalous “quantum Hall effect”. The quantum spin Hall effect (QSHE) usually refers to the quantized conductance in 2D topological insulators (TI). In this scenario, QSHE It is a quantum effect, but it’s not the quantum version of the spin Hall effect. There are chiral edge states and helical edge states. The helical edge state is referred to 1D channels on the edge of a 2D TI, but why are they not called chiral edge state? The Majorana fermions in condensed matter physics are strange quasiparticles (half of an electron) that come up in pairs. It shows some similarity to its high energy physics version but they are not the same. Some people prefer to call them Majorana zero modes because they usually have zero energy. The Dirac fermions and Wyle fermions in the condensed matter also differ from their high energy counterparts. In condensed matter physics, the Dirac fermions are massless thus linear dispersion, the Wyle fermions are a subset of Dirac fermions whose Dirac cones of different chiralities separate from each other. In high energy physics, the former is just fermions described by the Dirac equation, which may have non-zero mass, the latter is the massless subset of the former.