Plasmonics in two-dimensional Carbon Marco Polini Istituto Italiano

Plasmonics in two-dimensional Carbon
Marco Polini1,2
1
Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, I-16163, Genova (Italy)
2
NEST, Scuola Normale Superiore, I-56126, Pisa (Italy)
e-mail: [email protected]
Plasmons [1] are collective density oscillations that pertain to charged particles like electrons and
holes in solids. Although plasmons are often associated with metals, they are being actively
explored for graphene, the most studied two-dimensional material. Graphene plasmons (GPs) [2],
i.e. the self-sustained carrier density oscillations that occur in a doped graphene sheet, can achieve
active functionalities in diverse device types. For example, mid-infrared GPs have been used for
enhanced photodetection [3], vibrational sensing of surface-adsorbed polymers [4], and label-free
detection of protein monolayers [5].
In this talk I will first provide an up-to-date overview of the two most important figures of merit of
“graphene plasmonics”, namely i) the ratio between the GP and free-space illumination wavelength
and ii) the GP lifetime. I will emphasize the subtle difference between plasmon lifetime and Drude
transport scattering time, briefly presenting a theoretical framework that enables fully microscopic
calculations of GP lifetimes as limited by electron-electron [6], electron-impurity [7], and electronphonon [8] collisions. I will conclude this technical part by comparing theory with recent accurate
measurements [9] in high-quality graphene sheets encapsulated between boron nitride crystals.
Finally, I will conclude the talk by highlighting a number of relevant problems where many-body
methods at the intersection of quantum chemistry and condensed matter physics may shed light on
the collective behavior of few electrons trapped in small graphene nanostructures.
[1] G.F. Giuliani and G. Vignale, Quantum Theory of the Electron Liquid (Cambridge Univ. Press,
Cambridge, 2005).
[2] A.N. Grigorenko, M. Polini, and K.S. Novoselov, Nature Photon. 6, 749 (2012).
[3] F.H.L. Koppens, T. Mueller, Ph. Avouris, A.C. Ferrari, M.S. Vitiello, and M. Polini, Nature
Nanotech. 9, 780 (2014).
[4] Y. Li et al., Nano Lett. 14, 1573 (2014).
[5] D. Rodrigo et al., Science 349, 165 (2015).
[6] A. Principi, G. Vignale, M. Carrega, and M. Polini, Phys. Rev. B 88, 195405 (2013).
[7] A. Principi, G. Vignale, M. Carrega, and M. Polini, Phys. Rev. B 88, 121405(R) (2013).
[8] A. Principi, M. Carrega, M.B. Lundeberg, A. Woessner, F.H.L. Koppens, G. Vignale, and M.
Polini, Phys. Rev. B 90, 165408 (2014).
[9] A. Woessner, M.B. Lundeberg, Y. Gao, A. Principi, P. Alonso-González, M. Carrega, K.
Watanabe, T. Taniguchi, G. Vignale, M. Polini, J. Hone, R. Hillenbrand, and F.H.L. Koppens,
Nature Mater. 14, 421 (2015).