Insights into nanoplasmonics from first-principles time-dependent density functional simulations

Our optimal implementation of time-dependent density functional theory within linear response allows computing the optical properties of systems with several thousands of atoms [1,2].

We applied this method to study the dependence of the near-field enhancement and localization on the structural details of the plasmonic nano-gaps [3,4], the different size dispersion of the plasmon resonance of silver and sodium nanoparticles and how this behaviour correlates with the presence of 4d electrons in the Ag case [2], and more recently to describe valence EELS [5].

In this talk I will concentrate mostly in the correlation between transport properties across sub nanometric metallic gaps and the optical response of the system. In Ref. [6] we presented a study of the simultaneous evolution of the structure and the optical response of a plasmonic junction as the particles forming the cavity approach and retract. Atomic reorganizations are responsible for a large hysteresis of the plasmonic response of the system, which shows a jump-to-contact instability during the approach process and the formation of an atom-sized neck across the junction during retraction.

Our calculations show that, due to the conductance quantization in metal nanocontacts, small reconfigurations play a crucial role in determining the optical response. We observe abrupt changes in the intensity and spectral position of the plasmon resonances, and find a one-to-one correspondence between these jumps and those of the quantized transport as the neck cross-section diminishes. These results point out to a connection between transport and optics at the atomic scale at the frontier of current optoelectronics.

The author acknowledges financial support from FP7 FET-ICT project No. 610446 project, MINECO (Grant No. MAT2013-46593-C6-2-P), the Basque Dep. de Educación and the UPV/EHU (Grant No. IT-756-13).


[1] P. Koval, et al., J. Phys.: Cond. Matter 28, (2016) 214001
[2] M. Barbry, N. E. Koval, J. Aizpurua, D. Sánchez-Portal and P. Koval, submitted
[3] M. Barbry, et al., Nano Letters 354, (2015) 216
[4] M. Urbieta, et al., ACS Nano 12, (2018) 585-595
[5] M. Barbry, P. Koval and D. Sánchez-Portal, in preparation (2018)
[6] F. Marchesin, et al., ACS Photonics 3, (2016) 269-277

This site uses cookies.

Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and can only be disabled by changing your browser preferences.