paper

Unifying Interacting Nodal Semimetals: A New Route to Strong Coupling

arXiv:1812.05615 · doi:10.1103/PhysRevLett.123.207601

Abstract

We propose a general framework for constructing a large set of nodal-point semimetals by tuning the number of linearly ( $d_{L}$ ) and (at most) quadratically ( $d_{Q}$ ) dispersing directions. By virtue of such a unifying scheme, we identify a new perturbative route to access various strongly interacting non-Dirac semimetals with $d_{Q} > 0$ . As a demonstrative example, we relate a two dimensional anisotropic semimetal with $d_{L} = d_{Q} = 1$ , describing the topological transition between a Dirac semimetal and a normal insulator, and its three dimensional counterparts with $d_{L} = 1$ , $d_{Q} = 2$ . We address the quantum critical phenomena and emergence of non-Fermi liquid states with unusual dynamical structures within the framework of an $I^µ$ expansion, where $I^µ = 2 - d_{Q}$ , when these systems reside at the brink of charge- or spin-density-wave orderings, or an $s$ -wave pairing. Our results can be germane to two-dimensional uniaxially strained optical honeymcomb lattice, $I^\pm$ -(BEDT-TTF) $_{2} I_{3}$ .

5 pages, 3 figures; Published version