The true ground state of ν=0 (charge neutrality) monolayer-graphene quantum Hall has long been debated. The symmetry of the monolayer-graphene at ν=0 was analyzed by J. Alicea and P. A. Fisher in (PRB 2006), and canted anti-ferromagnet (CAF) was predicted by I. F. Herbut in (PRB 2007). However, the complete picture of the Hamiltonian was missing until the seminal paper by M. Kharitonov (PRB 2012), which predicts a phase transition from a vanilla insulator (CAF) to a topological insulator ferromagnet via Zeeman. This was later confirmed in the experiment (Andrea Young et. al. Nature 2014). Motivated by recent experiments (L. He et. al. PRB 2019, Ali Yazdani et. al. Science 2022, B. Sacepe Nature 2022) we revisit this phase diagram. We show that, generically, in the regime of interest there is a region of coexistence between magnetic and bond orders in the phase diagram in both continuum and lattice models.
Zoom link: https://icts-res-in.zoom.us/j/88190749750?pwd=RXdOanNndVJaRUtyMGhCR2hNUHlnUT09
Meeting ID: 881 9074 9750