We study in detail the transverse collective modes of simple holographic models in presence of electromagnetic Coulomb interactions. We render the Maxwell gauge field dynamical via mixed boundary conditions, corresponding to a double trace deformation in the boundary field theory. We consider three different situations: (i) a holographic plasma with conserved momentum, (ii) a holographic (dirty) plasma with finite momentum relaxation and (iii) a holographic viscoelastic plasma with propagating transverse phonons. We observe two interesting new features induced by the Coulomb interactions: a mode repulsion between the shear mode and the photon mode at finite momentum relaxation, and a propagation-to-diffusion crossover of the transverse collective modes induced by the finite electromagnetic interactions. Finally, at large charge density, our results are in agreement with the transverse collective mode spectrum of a charged Fermi liquid for strong interaction between quasi-particles, but with an important difference: the gapped photon mode is damped even at zero momentum. This property, usually referred to as anomalous attenuation, is produced by the interaction with a quantum critical continuum of states and might be experimentally observable in strongly correlated materials close to quantum criticality, e.g. in strange metals.
P. Nozieres and D. Pines, Theory of quantum liquids, Advanced Books Classics, Avalon Publishing, U.S.A. (1999).
D. Pines and D. Bohm, A collective description of electron interactions: II. Collective vs individual particle aspects of the interactions, Phys. Rev.85 (1952) 338 [INSPIRE].
S.A. Maier, Plasmonics: fundamentals and applications, Springer, New York, NY, U.S.A. (2007).
J. Jackson, Classical electrodynamics, Wiley, U.S.A. (1975).
M. Mitrano et al., Anomalous density fluctuations in a strange metal, Proc. Nat. Acad. Sci.115 (2018) 5392.
A.A. Husain et al., Crossover of charge fluctuations across the strange metal phase diagram, Phys. Rev.X 9 (2019) 041062.
T. Andrade, A. Krikun and A. Romero-Bermúdez, Charge density response and fake plasmons in holographic models with strong translation symmetry breaking, JHEP12 (2019) 159 [arXiv:1909.12242] [INSPIRE].
K. Trachenko and V.V. Brazhkin, Collective modes and thermodynamics of the liquid state, Rept. Prog. Phys.79 (2015) 016502 [arXiv:1512.06592].
C. Yang, M. Dove, V. Brazhkin and K. Trachenko, Emergence and evolution of the k-gap in spectra of liquid and supercritical states, Phys. Rev. Lett.118 (2017) 215502 [arXiv:1706.00836].
S. Conti and G. Vignale, Elasticity of an electron liquid, Phys. Rev.B 60 (1999) 7966 [cond-mat/9811214].
J.Y. Khoo, P.-Y. Chang, F. Pientka and I. Sodemann, Quantum paracrystalline shear modes of the electron liquid, arXiv:2001.06496.
H. Ohta and S. Hamaguchi, Wave dispersion relations in Yukawa fluids, Phys. Rev. Lett.84 (2000) 6026.
S.A. Khrapak, A.G. Khrapak, N.P. Kryuchkov and S.O. Yurchenko, Onset of transverse (shear) waves in strongly-coupled Yukawa fluids, J. Chem. Phys.150 (2019) 104503.
V. Nosenko, J. Goree and A. Piel, Cutoff wave number for shear waves in a two-dimensional Yukawa system (dusty plasma), Phys. Rev. Lett.97 (2006) 115001.
L. Tonks and I. Langmuir, Oscillations in ionized gases, Phys. Rev.33 (1929) 195.
K. Huang, Lattice vibrations and optical waves in ionic crystals, Nature167 (1951) 779.
J.M. Martín-García, xAct: efficient tensor computer algebra for the Wolfram language, https://www.xact.es.
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited
ArXiv ePrint: 1912.07321
About this article
Cite this article
Baggioli, M., Gran, U. & Tornsö, M. Transverse collective modes in interacting holographic plasmas. J. High Energ. Phys. 2020, 106 (2020). https://doi.org/10.1007/JHEP04(2020)106
- Holography and condensed matter physics (AdS/CMT)
- Gauge-gravity correspondence