Phonon Screening in High-Temperature Superconductors

C. C. Homes; A. W. McConnell; B. P. Clayman; D. A. Bonn; Ruixing Liang; W. N. Hardy; M. Inoue; H. Negishi; P. Fournier; R. L. Greene

doi:10.1103/PhysRevLett.84.5391

Phonon Screening in High-Temperature Superconductors

C. C. Homes, A. W. McConnell, B. P. Clayman, D. A. Bonn, Ruixing Liang, W. N. Hardy, M. Inoue, H. Negishi, P. Fournier, R. L. Greene

DOI 10.1103/PhysRevLett.84.5391 · Physical Review Letters

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Abstract

In good conductors optical phonons are usually screened, and therefore not observed. However, sharp features due to infrared-active modes in the copper-oxygen planes are observed in the optical conductivity of Pr1.85Ce0.15CuO4 and YBa2Cu3O6.95. Oscillator strengths indicate that the screening of these modes is poor or totally absent. These materials are compared with η−Mo4O11, in which lattice modes appear suddenly below the charge-density wave transition. It is proposed that poor screening in the cuprates originates from fluctuating charge inhomogeneities in the copper-oxygen planes.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
Pr1.85Ce0.15CuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
YBa2Cu3O6.95 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown