Pressure dependence of the single particle excitation in the charge-density-wave CeTe$_3$ system

Abstract We present new data on the pressure dependence at 300 K of the optical reflectivity of CeTe 3 ,which undergoes a charge-density-wave (CDW) phase transition well above room temperature. Thecollected data cover an unprecedented broad spectral range from the infrared up to the ultraviolet,which allows a robust determination of the gap as well as of the fraction of the Fermi surface affectedby the formation of the CDW condensate. Upon compressing the lattice there is a progressiveclosing of the gap inducing a transfer of spectral weight from the gap feature into the Drudecomponent. At frequencies above the CDW gap we also identify a power-law behavior, consistentwith findingsalong the RTe 3 series (i.e., chemical pressure)and suggestive of a Tomonaga-Luttingerliquid scenario at high energy scales. This newest set of data is placed in the context of our previousinvestigations of this class of materials and allows us to revisit important concepts for the physicsof CDW state in layered-like two-dimensional systems.