"Persistent low-energy phonon broadening near the charge-order q vector in the bilayer cuprate Bi2Sr2CaCu2O8+δ"

Y. He: S. Wu, Y. Song, W.-S. Lee, A. H. Said, A. Alatas, A. Bosak, A. Girard,S. M. Souliou, A. Ruiz, M. Hepting, M. Bluschke, E. Schierle, E. Weschke, J.-S. Lee, H. Jang, H. Huang, M. Hashimoto, D.-H. Lu, D. Song, Y. Yoshida, H. Eisaki, Z.-X. Shen, R. J. Birgeneau, M. Yi,and A. Frano; Physical Review B, 07/02/18.

Additional Authors: S. Wu, Y. Song, W.-S. Lee, A. H. Said, A. Alatas, A. Bosak, A. Girard,S. M. Souliou, A. Ruiz, M. Hepting, M. Bluschke, E. Schierle, E. Weschke, J.-S. Lee, H. Jang, H. Huang, M. Hashimoto, D.-H. Lu, D. Song, Y. Yoshida, H. Eisaki, Z.-X. Shen, R. J. Birgeneau, M. Yi,and A. Frano

Abstract:

We report a persistent low-energy phonon broadening around qB∼0.28 reciprocal lattice unit (r.l.u.) along the Cu-O bond direction in the high-Tcuprate Bi2Sr2CaCu2O8+δ (Bi-2212). We show that such broadening exists both inside and outside the conventional charge-density wave (CDW) phase, via temperature-dependent measurements in both underdoped and heavily overdoped samples. Combining inelastic hard x-ray scattering, diffuse scattering, angle-resolved photoemission spectroscopy, and resonant soft x-ray scattering at the Cu L3-edge, we exclude the presence of a CDW in the heavily overdoped Bi-2212 similar to that observed in the underdoped systems. Finally, we discuss the origin of such anisotropic low-energy phonon broadening and its potential precursory role to the CDW phase in the underdoped region.