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Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). Charge density wave (CDW) order has been shown to compete and coexist with superconductivity in underdoped cuprates. Theoretical proposals for the CDW order include an unconventional d-symmetry form factor CDW, evidence for which has emerged from measurements, including resonant soft x-ray scattering (RSXS) in YBa2Cu3O6+x (YBCO). Here, we revisit RSXS measurements of the CDW symmetry in YBCO, using a variation in the measurement geometry to provide enhanced sensitivity to orbital symmetry. We show that the (0 0.31 L) CDW peak measured at the Cu L edge is dominated by an s form factor rather than a d form factor as was reported previously. In addition, by measuring both (0.31 0 L) and (0 0.31 L) peaks, we identify a pronounced difference in the orbital symmetry of the CDW order along the a and b axes, with the CDW along the a axis exhibiting orbital order in addition to charge order.

We present far infrared reflectance measurements of UBe13 and URu2Si2 down to a temperature of 2 K. At low temperatures the optical conductivity of both materials may be described in terms of free charge carriers with frequency and temperature dependent scattering rates and mass enhancements. The 'coherent regime' occurs at too low a temperature in UBe13 to be observed in our measurements, but it can be observed in URu2Si2. In addition to the behaviour of the charge carriers URu2Si2 exhibits two strong phonon lines at 109 cm-1 and 378 cm-1 and below the magnetic transition temperature there is an additional absorbtion feature near 50 cm-1. © 1988.

We present far infrared reflectance measurements of UBe13 and URu2Si2 down to a temperature of 2 K. At low temperatures the optical conductivity of both materials may be described in terms of free charge carriers with frequency and temperature dependent scattering rates and mass enhancements. The 'coherent regime' occurs at too low a temperature in UBe13 to be observed in our measurements, but it can be observed in URu2Si2. In addition to the behaviour of the charge carriers URu2Si2 exhibits two strong phonon lines at 109 cm-1 and 378 cm-1 and below the magnetic transition temperature there is an additional absorbtion feature near 50 cm-1. © 1988.

We report on the optical properties of the heavy fermion superconductor UBe13 from 0.050 to 2eV. The reflectance shows sharp structure at low frequencies superimposed on a smooth decrease down to 50% at 1.6eV. The ThBe13 compound is shown for comparison as a non-heavy fermion system. Kramers-Kronig analysis of reflectance measurements yields sharp interband structure in UBe13 in the 0.1 eV region. In the far IR, above 100 K, the material shows normal Drude behavior: the optical conductivity agrees well with the d.c. conductivity. © 1987.

We report on the optical properties of the heavy fermion superconductor UBe13 from 0.050 to 2eV. The reflectance shows sharp structure at low frequencies superimposed on a smooth decrease down to 50% at 1.6eV. The ThBe13 compound is shown for comparison as a non-heavy fermion system. Kramers-Kronig analysis of reflectance measurements yields sharp interband structure in UBe13 in the 0.1 eV region. In the far IR, above 100 K, the material shows normal Drude behavior: the optical conductivity agrees well with the d.c. conductivity. © 1987.