Tomonaga–Luttinger Liquid–Fermi Liquid Transition in Chain of PrBa2Cu4O8

Optical reflection spectroscopy perpendicular to the double-chain of PrBa 2 Cu 4 O 8 clarified that carriers in the plane transfer to the chain almost completely as temperature decreases from 295 to 150 K. Many anomalies around 150 K can be explained by the transfer of carriers. The temperature and Zn substitution effects suggest that the chains are in the Fermi liquid state when the carrier density is close to 0.5/Cu(1) and in the Tomonaga–Luttinger liquid state when the carrier density is 0.4/Cu(1).