Landau ordering phase transitions beyond the Landau paradigm

Understand

Continuous phase transitions associated with the onset of a spontaneously broken symmetry are thought to be successfully described by the Landau-Ginzburg-Wilson-Fisher theory of fluctuating order parameters.

• In this work we show that such transitions can admit new universality classes which cannot be understood in terms of a theory of order parameter fluctuations.
• We explicitly demonstrate continuous time reversal symmetry breaking quantum phase transitions of $3+1$-D bosonic systems described by critical theories expressed in terms of a deconfined gauge theory with massless Dirac fermions instead of the fluctuating Ising order parameter.
• We dub such phase transitions "Landau transitions beyond Landau description" (LBL).