Who: Tomas Neuman, Institut de Physique et Chimie des Matériaux de Strasbourg, France
Place: Online Seminar, Donostia International Physics Center
Date: Friday, 26 February 2021, 12:00
Vibrational, electronic, and spin excitations in molecules can identify molecules in spectroscopy, but also play a role in molecular chemical reactivity, or find technological applications e.g. in superresolution microscopy or infrared-to-optical transduction . Recently, excitations in single molecules and molecular networks have been proposed to serve as physical platforms for qubits or for nanoscale sources of non-classical photon states . To fully take advantage of the molecular platforms it is therefore necessary to elucidate how molecular excitations can be detected, engineered, and controlled, especially on the single- or a few-molecular scale.
I will discuss how nanoscale metallic structures supporting collective electronic excitations - plasmons - can be used to enhance the interaction between photons and molecular excitations and thus detect and control them, and even to break well-established spectroscopic selection rules . Full understanding of the plasmon-mediated light-matter interactions also enables novel spectroscopic methods exploiting the correlated information about transport and optical properties of molecules. A particular example of the electroluminescence spectroscopy in scanning tunneling microscope used to elucidate the tautomerization dynamics in free-base phthalocyanine molecules will be discussed .
Finally, I will elaborate on the potential of molecules for electro-optics and quantum technologies exploiting the molecular optical activity and spin properties. In particular, the potential of molecular spins to serve as optically, mechanically and magnetically controllable qubits , or the possibilities to manipulate spin-forbidden molecular transitions will be discussed.
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 T. Neuman, R. Esteban, D. Casanova, F.J. García-Vidal, J. Aizpurua, Nano Letters 18 (4), 2358-2364 (2018).
 B. Doppagne, T. Neuman, R. Soria-Martinez, et al., Nature Nanotechnology 15 (3), 207-211 (2020).
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Host: Javier Aizpurua