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Itinerant quantum critical point with frustration and a non-Fermi liquid

2018; American Physical Society; Volume: 98; Issue: 4 Linguagem: Inglês

10.1103/physrevb.98.045116

2469-9977

Zi Hong Liu, Xiao Yan Xu, Yang Qi, Kai Sun, Zi Yang Meng,

Quantum many-body systems

Employing the self-learning quantum Monte Carlo algorithm, we investigate the frustrated transverse-field triangle-lattice Ising model coupled to a Fermi surface. Without fermions, the spin degrees of freedom undergoes a second-order quantum phase transition between paramagnetic and clock-ordered phases. This quantum critical point (QCP) has an emergent U(1) symmetry and thus belongs to the (2+1)D XY universality class. In the presence of fermions, spin fluctuations introduce effective interactions among fermions and distort the bare Fermi surface towards an interacting one with hot spots and Fermi pockets. Near the QCP, non-Fermi-liquid behavior are observed at the hot spots, and the QCP is rendered into a different universality with Hertz-Millis type exponents. The detailed properties of this QCP and possibly related experimental systems are also discussed.