Spectral signatures of critical charge and spin fluctuations in cuprates

Abstract

We discuss how Raman spectra of high temperature superconducting cuprates are affected by nearly-critical spin and charge collective modes, which are coupled to charge carriers near a stripe quantum critical point. We find that specific fingerprints of nearly-critical collective modes can be observed and that the selectivity of Raman spectroscopy in momentum space may be exploited to distinguish the spin and charge contribution. We apply our results to discuss the spectra of high-T_c superconducting cuprates finding that the collective modes should have masses with substantial temperature dependence in agreement with their nearly critical character. Moreover spin modes have larger masses and are more diffusive than charge modes indicating that in stripes the charge is nearly ordered, while spin modes are strongly overdamped and fluctuating with high frequency.

6 pages and 3 figures, invited paper to the conference SCES 08, Buzios/Rio, Brazil

References in corpus (8)

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Cited by in corpus (7)

• Electrodynamics of Correlated Electron Materials
• Bosons in high temperature superconductors: an experimental survey
• Quantitative comparison of single- and two-particle properties in the cuprates
• Signatures of nematic quantum critical fluctuations in the Raman spectra of lightly doped cuprates
• Optical and Hall conductivities of a thermally disordered two-dimensional spin-density wave: two-particle response in the pseudogap regime of electron-doped high-$T_c$ superconductors
• Dynamical charge and spin density wave scattering in cuprate superconductor
• SCES '08 - concluding remarks