Researchers from CIC-nanoGUNE (San Sebastián, Spain), in collaboration with the Donostia International Physics Center (San Sebastián, Spain), Materials Physics Center (CFM, CSIC-UPV/EHU, San Sebastián, Spain) and University of Oviedo demonstrate a new way to strongly couple infrared light and molecular vibrations, by utilizing phonon polariton nanoresonators made of hexagonal boron nitride, a Van der Waals material.
The results published in Light: Science & Applications (“Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit”) open new avenues for fundamental studies of vibrational strong coupling, as well as for the development of novel infrared sensors for chemical recognition of very small amounts of molecules.
The interaction of light and matter at the nanoscale is a key element for many fundamental studies and technological applications, ranging from light harvesting to the detection of small amounts of molecules.
During the last decades, many strategies have been implemented in order to enhance nanoscale light-matter interactions. One approach is based on concentrating light with the help of propagating and localized surface plasmon polaritons, which are collective electron oscillations in metals or semiconductors that are coupled to light. These electromagnetic excitations can concentrate light into nanoscale spots, so-called hotspots. At mid-infrared frequencies, they enable, for example, the detection of tiny amounts of molecules. This method is called surface-enhanced infrared absorption (SEIRA) spectroscopy. However, typical mid-infrared plasmonic structures suffer from large losses and do not achieve ultimate light concentration.
An interesting but much less explored approach for enhancing nanoscale light-matter interaction is based on infrared-phononic materials, in which light couples to crystal lattice vibrations to form so-called phonon polaritons. “Phonon-polariton resonators offer much lower losses and field confinement than their mid-infrared plasmonic counterparts. For that reason, we decided to develop and apply infrared-phononic resonators to enhance the coupling of infrared light to molecular vibrations” says postdoc Marta Autore, first author of the paper.

Image Credit: Ella Maru Studio
News This Week
Self-Organizing Light Could Transform Computing and Communications
USC engineers have demonstrated a new kind of optical device that lets light organize its own route using the principles of thermodynamics. Instead of relying on switches or digital control, the light finds its own [...]
Groundbreaking New Way of Measuring Blood Pressure Could Save Thousands of Lives
A new method that improves the accuracy of interpreting blood pressure measurements taken at the ankle could be vital for individuals who are unable to have their blood pressure measured on the arm. A newly developed [...]
Scientist tackles key roadblock for AI in drug discovery
The drug development pipeline is a costly and lengthy process. Identifying high-quality "hit" compounds—those with high potency, selectivity, and favorable metabolic properties—at the earliest stages is important for reducing cost and accelerating the path [...]
Nanoplastics with environmental coatings can sneak past the skin’s defenses
Plastic is ubiquitous in the modern world, and it's notorious for taking a long time to completely break down in the environment - if it ever does. But even without breaking down completely, plastic [...]
Chernobyl scientists discover black fungus feeding on deadly radiation
It looks pretty sinister, but it might actually be incredibly helpful When reactor number four in Chernobyl exploded, it triggered the worst nuclear disaster in history, one which the surrounding area still has not [...]
Long COVID Is Taking A Silent Toll On Mental Health, Here’s What Experts Say
Months after recovering from COVID-19, many people continue to feel unwell. They speak of exhaustion that doesn’t fade, difficulty breathing, or an unsettling mental haze. What’s becoming increasingly clear is that recovery from the [...]
Study Delivers Cancer Drugs Directly to the Tumor Nucleus
A new peptide-based nanotube treatment sneaks chemo into drug-resistant cancer cells, providing a unique workaround to one of oncology’s toughest hurdles. CiQUS researchers have developed a novel molecular strategy that allows a chemotherapy drug to [...]
Scientists Begin $14.2 Million Project To Decode the Body’s “Hidden Sixth Sense”
An NIH-supported initiative seeks to unravel how the nervous system tracks and regulates the body’s internal organs. How does your brain recognize when it’s time to take a breath, when your blood pressure has [...]
Leave A Comment