12 September 2016

The ability to investigate femtosecond dynamics on a single nanoparticle level remained an elusive dream for years. Even though each field, single molecule detection on one hand and femtosecond spectroscopy in the condensed phase on the other, was thriving already in the ’90s, it was not until the dawn of the 21st century that the two fields gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Combining ultrafast with ultrasmall, that is femto with nano, allows to disentangle fundamental processes such as the intraparticle and interparticle energy redistribution and charge transfer. It enables, among others, observation of the electronic dephasing and coherent processes associated with resonances in single molecules, QDs, and plasmonic nanoparticles.

Now, ICFO researchers Dr. Lukasz Piatkowski and Dr. Nicolò Accanto, led by ICREA Prof. Niek F. van Hulst, have recently published a review article in ACS Photonics entitled “Ultrafast meets ultrasmall: controlling nanoantennas and molecules”, where they give a timely snapshot of the current state of the ultrafast nanoscopy field. They present the advances achieved regarding pulse control and ultrafast coherent excitation of both plasmonic nanoparticles and individual molecular systems, mainly based on the discoveries and accomplishments made by their research group at ICFO. In their review, the ICFO scientists have summarized their efforts in understanding and manipulating the different ultrafast regimes, coherent and incoherent, in both single molecules and plasmonic nanostructures. They covered topics that span from incoherent dynamics in a single molecule to phase control of femtosecond pulses, the use of plasmonic antennas for ultrafast nanophotonics, detection and control of femtosecond coherence and vibrational wave packet dynamics in single molecules, as well as phase-controlled detection of energy transfer in light harvesting complexes, among others.

As part of their concluding remarks, they emphasize that ultrafast nanoscopy is definitely a thriving field and that significant advances can be expected in the near future.

Their study has been selected to grace the cover of the August issue of ACS Photonics, having ICFO appear on the cover of ACS Photonics in two consecutive issues.

• Link to the paper
• Link to the cover of ACS Photonics
• Link to the research group led by ICREA Prof. at ICFO Niek van Hulst