Charge density waves with nontrivial orbital textures in rare earth tritellurides

Motivated by recent experiments reporting unconventional collective modes in the charge density wave (CDW) state of rare earth tritellurides RTe3, we derive a CDW Ginzburg-Landau theory that allows for nontrivial orbital order from a multiorbital microscopic model on the square net. Our analysis reveals unconventional CDWs where order parameters with distinct orbital character coexist due to an approximate symmetry of the low-energy model, which becomes exact in the limit of nearest-neighbor-only hopping and decoupled px,py orbitals. Because of this coexistence, the resulting CDW pattern displays an orbital texture that generally breaks additional symmetries of the lattice in addition to those explicitly broken by the CDW wave vector. We find two competing phases that differ in whether they break or preserve inversion and vertical mirror symmetries. We explain the mechanisms that favor each outcome and discuss experimental probes that can distinguish the different phases.