Datensatz

Zusammenfassung

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 epsilon expansion, where epsilon = 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, alpha-(BEDT-TTF)(2)I-3.