Leaders: Andrei Borissov and François Aguillon

The main research effort in recent years has been to use TDDFT and classical approaches to study quantum effects such as non-local screening and (possibly inelastic) tunneling in plasmonics.

Coupling light with plasmons, collective excitations of conduction electrons in metals, allows to control and enhance optical fields over nanometric distances, much smaller than the optical wavelength. We have been able to establish the role played by non-local screening, electron propagation, and especially by electron tunneling in determining the linear and non-linear optical response of plasmonic systems.

Subsequently, the idea is to study how these quantum effects can be used for active electrical control of plasmon modes. This paves the way for optoelectronic devices at the nanometric scale.

Techniques: TD-DFT, ab initio calculations.

News:
— Just published: “Fluorescence from a single-molecule probe directly attached to a plasmonic STM tip”, Nature Communications 15, 9733 (2024): we demonstrate that a PTCDA molecule retains its intrinsic emission properties even when directly attached to the plasmonic tip of a scanning probe microscope. This atomic-scale sensor could be used, in the near future, in resonant energy transfer microscopy experiments where it would provide lateral and axial precision at the atomic scale.

Highlights:

A scanning fluorescent nanoprobe based on a single molecule suspended at the tip of an STM

The plasmonic tip of an STM is functionalized with a single fluorescent molecule and scanned on a plasmonic substrate. Tunneling current flowing through the tip-molecule-substrate junction generates a spectrally narrow light emission corresponding to the fluorescence of the negatively charged molecule suspended on the tip apex. We demonstrate that the spectral width of the emission peak can be used as a probe of the exciton-plasmon coupling strength and that the energy of the emitted photons is governed by the interactions of the molecule with its environment.

Article : Niklas Friedrich, Anna Rosławska, Xabier Arrieta, Katharina Kaiser, Michelangelo Romeo, Eric Le Moal, Fabrice Scheurer, Javier Aizpurua, Andrei G. Borisov, Tomáš Neuman & Guillaume Schull, “Fluorescence from a single-molecule probe directly attached to a plasmonic STM tip”, Nat. Commun. 15, 9733 (2024), pdf

Graphene nanostructures have a nonlinear response to polarized light that is very different from that of macroscopic graphene.

Using the tight-binding approximation and the time-dependent density matrix approach, we theoretically describe the nonlinear response of plasmonic graphene nanostructures to circularly polarized light. The intensity and polarization of the emitted harmonics depend on the symmetry of the system and can be analyzed by applying Neumann’s principle. For nanomaterials comprising thousands of carbon atoms, it is the symmetry of the carbon atom arrangement at the atomic scale that determines the nonlinear response. Therefore, it could be very different from the nonlinear response predicted using the macroscopic geometry. We show that symmetry breaking for example by lattice defects strongly affects the nonlinear response of graphene nanomaterials to circularly polarized light. Our work extends theoretical studies of the nonlinear optical properties of graphene nanomaterials to spin-carrying light beams.

Article : François Aguillon et Andrei G. Borisov, “Nonlinear Response of Nanostructured Graphene to Circularly Polarized Light”, J. Phys. Chem. C 128, 16576 (2024), pdf

Publications (since 2020) :

Model description of electron transfer between PTCDA molecule and metal surface upon molecular adsorption and STM manipulation, A. G. Borisov, Phys. Rev. B 110 (7), 075413 (2024), pdf

Nonlinear Optical Response of a Plasmonic Nanoantenna to Circularly Polarized Light: Rotation of Multipolar Charge Density and Near-Field Spin Angular Momentum Inversion, M. Quijada, A. Babaze, J. Aizpurua, A. G. Borisov, ACS Photonics 10 (11), 3963-3975 (2023), pdf

Dispersive surface-response formalism to address nonlocality in extreme plasmonic field confinement, A. Babaze, T. Neuman, R. Esteban, J. Aizpurua, A. G. Borisov, Nanophotonics 12 (16), 3277-3289 (2023), pdf

Atomic-Scale Defects Might Determine the Second Harmonic Generation from Plasmonic Graphene Nanostructures, F. Aguillon, A. G. Borisov, J. Phys. Chem. Lett. 14 (1), 238-244 (2023), pdf

Quantum surface effects in the electromagnetic coupling between a quantum emitter and a plasmonic nanoantenna: time-dependent density functional theory vs. semiclassical Feibelman approach, A. Babaze, E. Ogando, P. E. Stamatopoulou, C. Tserkezis, N. A. Mortensen, J. Aizpurua, A. G. Borisov, R. Esteban, Opt. Express 30 (12), 21159-21183 (2022), pdf

Mapping Lamb, Stark and Purcell effects at a chromophore-picocavity junction with hyper-resolved fluorescence microscopy, A. Roslawska, T. Neuman, B. Doppagne, A. G. Borisov, M. Romeo, F. Scheurer, J. Aizpurua, G. Schull, Phys. Rev. X 12, 011012 (2022), pdf

Time-dependent density functional theory calculations of electronic friction in non-homogeneous media, N. E. Koval, D. Sánchez-Portal, A. G. Borisov, R. D. Muiño, Phys. Chem. Chem. Phys. 24 (34), 20239-20248 (2022), pdf

Atomic-scale control of plasmon modes in graphene nanoribbons, F. Aguillon, D. C. Marinica, A. G. Borisov, Phys. Rev. B 105 (8), L081401 (2022), pdf

Effect of a Dielectric Spacer on Electronic and Electromagnetic Interactions at Play in Molecular Exciton Decay at Surfaces and in Plasmonic Gaps, F Aguilar-Galindo, M Zapata-Herrera, S Díaz-Tendero, J Aizpurua, A. G. Borisov, ACS Photonics 8 (12), 3495-3505 (2021), pdf

Plasmons in Graphene Nanostructures with Point Defects and Impurities, F Aguillon, DC Marinica, AG Borisov, J. Phys. Chem. C 125 (39), 21503-21510 (2021), pdf

Electronic Exciton–Plasmon Coupling in a Nanocavity Beyond the Electromagnetic Interaction Picture, A Babaze, R Esteban, AG Borisov, J Aizpurua, Nano Letters 21 (19), 8466-8473 (2021), pdf

Molecule Detection with Graphene Dimer Nanoantennas, F Aguillon, DC Marinica, AG Borisov, The Journal of Physical Chemistry C 124 (51), 28210-28219 (2020), pdf

Probing the radiative electromagnetic local density of states in nanostructures with a scanning tunneling microscope, S Cao, M Zapata-Herrera, A Campos, E Le Moal, S Marguet, G Dujardin, M Kociak, J Aizpurua, AG Borisov, E Boer-Duchemin, ACS Photonics 7 (5), 1280-1289 (2020), pdf

Second-Harmonic Generation from a Quantum Emitter Coupled to a Metallic Nanoantenna, A Babaze, R Esteban, J Aizpurua, AG Borisov, ACS Photonics 7 (3), 701-713 (2020), pdf