Universal Fermi-surface anisotropy renormalization for interacting Dirac fermions with long-range interactions*

Recent evidence suggest an intriguing universal relationship between the Fermi surface anisotropy of the non-interacting parent two-dimensional electron gas and the strongly correlated composite Fermi liquid formed in a strong magnetic field close to half-filling. Inspired by these observations, we explore more generally the question of anisotropy renormalization in interacting 2D Fermi systems. Using a recently developed [1] non-perturbative and numerically-exact projective quantum Monte Carlo simulation as well as other numerical and analytic techniques, only for Dirac fermions with long-range Coulomb interactions do we find a universal square-root decrease of the Fermi-surface anisotropy [2]. Our proposed universality can be tested in several anisotropic Dirac materials including graphene, topological insulators and organic conductors.

[1] H-K. Tang, J. Leaw, J. Rodrigues, I. Herbut, P. Sengupta, F. Assad and S. Adam, Science, 361, 570 (2018);

[2] J. Leaw, H-K. Tang, M. Trushin, F. F. Assaad, S. Das Sarma, and S. Adam, arXiv:1809.07775