New Luttinger liquid physics from photoemission on Li${}_{0.9}$Mo${}_6$O${}_{17}$

Temperature dependent high resolution photoemission spectra of quasi-1 dimensional Li${}_{0.9}$Mo${}_6$O${}_{17}$ evince a strong renormalization of its Luttinger liquid density-of-states anomalous exponent. We trace this new effect to interacting charge neutral critical modes that emerge naturally from the two-band nature of the material. Li${}_{0.9}$Mo${}_6$O${}_{17}$ is shown thereby to be a paradigm material that is capable of revealing new Luttinger physics.