Orbital symmetry of charge density wave order in La1.875Ba0.125CuO4 and YBa2Cu3O6.67

Understand

Recent theories of charge density wave (CDW) order in high temperature superconductors have predicted a primarily d CDW orbital symmetry.

• Here, we report on the orbital symmetry of CDW order in the canonical cuprate superconductors La1.875Ba0.125CuO4 (LBCO) and YBa2Cu3O6.67 (YBCO), using resonant soft x-ray scattering and a model mapped to the CDW orbital symmetry.
• From measurements sensitive to the O sublattice, we conclude that LBCO has predominantly s' CDW orbital symmetry, in contrast to the d orbital symmetry recently reported in other cuprates.
• Additionally, we show for YBCO that the CDW orbital symmetry differs along the a and b crystal axes and that these both differ from LBCO.