  We perform a symmetry analysis of a 2D electron system in HgTe/HgCdTe quantum
wells in the situation when the chemical potential is outside of the gap, so
that the bulk of the quantum well is conducting. In order to investigate
quantum transport properties of the system, we explore symmetries of the
low-energy Hamiltonian which is expressed in terms of two flavors of Dirac
fermions, and physically important symmetry-breaking mechanisms. This allows us
to predict emerging patterns of symmetry breaking that control the weak
localization and antilocalization showing up in transverse-field
magnetoresistance.
