Angle-resolved photoemission spectroscopy study of rare-earth tritelluride charge density wave compounds: RTe3 (R = Pr, Er)

Abstract The electronic structures of layered rare-earth tritelluride R Te 3 ( R = Pr, Er) charge density wave (CDW) compounds have been investigated by performing R 4 d → 4 f resonant photoemission spectroscopy (RPES) and angle-resolved photoemission spectroscopy (ARPES) measurements for high-quality single crystals. R 4 d → 4 f RPES measurements reveal that the R 4 f states do not contribute directly to the CDW formation in R Te 3 but that the R 4 f -Te 5 p hybridization in PrTe 3 is significantly larger than that in ErTe 3 . In the photon-energy maps for the Fermi-edge ( E F )-crossing states in R Te 3 , straight vertical dispersions are observed along k c , demonstrating the 2D character for the near- E F states in both R = Pr and Er. This finding implies the weak interlayer interaction between R -Te(1) and Te(2)–Te(3) layers, which is supported by the similar linear dichroism in ARPES for PrTe 3 and ErTe 3 . The CDW-induced Fermi surface of PrTe 3 exhibits two-fold symmetric features while that of ErTe 3 exhibits four-fold symmetric features. This finding reveals different CDW distortions in PrTe 3 and ErTe 3 , the origin of which is likely to be different ionic sizes of R ions and different R 4 f -Te 5 p hybridization.