Zi Yang Meng

Tue, 19/03/2019 - 12:00 to 13:30

Danciger B building, Seminar room
Title: Revealing quantum criticality from Monte Carlo simulations Speaker: Zi Yang Meng, IOP, CAS Abstract: Metallic quantum criticality is among the central theme in the understanding of correlated electronic systems, and converging results between analytical and numerical approaches are still under calling. In this talk, I will present recent developments in large-scale quantum Monte Carlo simulations of correlated electron systems. Fresh results on itinerant quantum critical points, i.e. the critical phenomena arising from the strong coupling between Fermi surface and bosonic fluctuations will be discussed. In the case of antiferromagnetic quantum critical point, we found that the antiferromagnetic spin fluctuations introduce effective interactions among fermions and the fermions in return render the bare bosonic critical point into a new universality, different from both the bare Ising universality class and the Hertz-Mills-Moriya RPA prediction. At the quantum critical point, a finite anomalous dimension is observed in the bosonic propagator, and fermions at hot spots evolve into a non-Fermi-liquid. In the end, I will also discuss the extension of such numerical setting to the situation of gauge fields coupled to matter fields, which is fundamentally connected to the understanding of deconfined quantum criticality. Reference: Phys. Rev. X 7, 031058 (2017), arXiv:1807.07574, arXiv:1808.08878