Alexander Govorov (Ohio University)

Date: Mon. September 20th, 2021, 12:45 pm-1:45 pm
Location: Rockefeller 221 (Foldy) & Zoom (ID: 94848866824 Passcode: 616859)
Website: http://www.phy.ohio.edu/~govorov/

Plasmonic Metastructures and Bio-Assemblies: Chirality, DNA-origami, and hot electrons

Alexander O. Govorov

Department of Physics and Astronomy, Ohio University, Athens, USA; govorov@ohio.edu

Abstract.– Plasmonic nanostructures and metamaterials are very efficient at the absorption and scattering of light. The studies to be presented in this talk concern special designs of hybrid nanostructures with electromagnetic hot spots, where the electromagnetic field becomes strongly enhanced and spatially concentrated. Overall, plasmonic nanostructures with hot spots demonstrate strongly amplified optical and energy-related effects, and this talk will review some of such phenomena. (1) Using nanoparticle arrays made of different metals, one can transfer plasmonic signals coherently and with minimal losses [1]. (2) Plasmonic hot spots efficiently generate energetic electrons, which can be used for photochemistry and photodetection [2,3,4]. (3) Nanostructures with small interparticle gaps can strongly enhance heat’s optical generation and confine high photo-temperatures in small volumes [5,6,7]. (4) Colloidal nanocrystal assemblies and metastructures with plasmon resonances allow us to strongly enhance the chiral optical responses (circular dichroism) of biomolecules and to induce chiral photo-chemical effects [8,9,10,11].

References
[1] E.-M. Roller et al., Nature Physics, 13, 761 (2017).
[2] A.O. Govorov, H. Zhang, H.V. Demir and Y. K. Gun’ko, Nano Today 9, 85 (2014).
[3] H. Harutyunyan et al., Nature Nanotech. 10, 770 (2015).
[4] L. V. Besteiro et al, Nano Today, 27, 120 (2019).
[5] A. O. Govorov and H. Richardson, Nano Today 2, 20 (2007).
[6] C. Jack et al., Nat. Commun. 7, 10946 (2016).
[7] X.-T. Kong et al., Nano Letters, 18, 2001 (2018).
[8] A. O. Govorov et al., Nano Letters 10, 1374–1382 (2010).
[9] A. Kuzyk et al., Nature 483, 311 (2012).
[10] T. Liu et al., Nano Letters, 19, 1395–1407 (2019).
[11] K. Martens, et al., Nat. Commun., 12, 2025 (2021).

 

Host: Walter Lambrecht