Non-Fermi Liquid at (2+1)D Ferromagnetic Quantum Critical Point

oleh: Xiao Yan Xu, Kai Sun, Yoni Schattner, Erez Berg, Zi Yang Meng

Format: Article
Diterbitkan: American Physical Society 2017-09-01

Deskripsi

We construct a two-dimensional lattice model of fermions coupled to Ising ferromagnetic critical fluctuations. Using extensive sign-problem-free quantum MonteĀ Carlo simulations, we show that the model realizes a continuous itinerant quantum phase transition. In comparison with other similar itinerant quantum critical points (QCPs), our QCP shows a much weaker superconductivity tendency with no superconducting state down to the lowest temperature investigated, hence making the system a good platform for the exploration of quantum critical fluctuations. Remarkably, clear signatures of non-Fermi liquid behavior in the fermion propagators are observed at the QCP. The critical fluctuations at the QCP partially resemble Hertz-Millis-Moriya behavior. However, careful scaling analysis reveals that the QCP belongs to a different universality class, deviating from both (2+1)D Ising and Hertz-Millis-Moriya predictions.