Q&A: The new method confines light inside an organic material to create a hybrid quantum state

An international team of scientists led by the University of Ottawa has gone back to the kitchen cupboard to develop a recipe that combines organic matter and light to create quantum states.

Professor Jean-Michel Menard, leader of the Ultrafast Terahertz Spectroscopy Group in the Faculty of Science, coordinated with Dr. Claudio Genes at the Max Planck Institute for Light Science (Germany) and with Iridian Spectral Technologies (Ottawa) to develop a design. A device that can effectively change the properties of materials using quantum superposition with light.

The team designed a two-dimensional planar resonator—known as a metasurface—that absorbed light. Using a spray coating technique, they deposited a thin layer of glucose on the metasurface to create a strong interaction between light and glucose molecules in the sugar.

Their concept brings researchers closer to the technological ability to capture some of the unique properties of quantum systems that exist in a hybrid state of light and matter.

Faculty of Science professors Ksenia Dolgaleva and Robert Boyd, along with lead author Professor Menard, whose findings are published in Nature communication.

What did you decide and what did you find?

We present an innovative and efficient technique for the synthesis of quantum organic materials by combining light and matter. When light in the far-infrared region—at terahertz (THz) frequencies—is injected into an organic material, it can integrate with molecules, leading to a quantum state that exhibits unique properties. It is of increasing interest due to their potential application in breeding. Physical and chemical properties of matter, these attractive states occur only under certain conditions.

Our team identified this critical condition and developed a telephotonic trap, or device, to effectively confine light in a small volume of space for a significant amount of time. This trap creates a strong coupling regime between light and a molecular complex.

Unlike previous methods that relied on optical cavities made from two facing mirrors, we instead designed and tested a 2D planar resonator called a metasurface. This metasurface effectively allows optical confinement in a planar geometry and opens practical new avenues to explore the quantum regime of strong light-matter interactions.

Finally, we combined metasurfaces with traditional cavity geometries to form hybrid cavity architectures and observe enhanced coupling strength between light and matter. These results are shown with glucose, an organic compound with useful properties in the fields of biology and medicine.

Why use THz light and sugar?

Terahertz light is particularly interesting because it can vibrate many molecules, including the glucose molecules in the sugar. The vibrational energy of molecules is intricately related to their properties, including their ability to engage in chemical reactions with other molecules.

Therefore, by designing platforms that enable strong coupling between terahertz light and the vibration of molecules, which are the fundamental building blocks of organic matter, we have the potential to alter their properties to potentially gain control over the fundamental mechanisms of life. .

What did you end up finding with your research?

We discovered efficient approaches for coupling terahertz light and matter. The most promising concept is based on a structured metal surface, metasurface, incorporated into the design of a photonic cavity. As a result, the light is doubly trapped and strongly confined inside the device.

Our robust plug-and-play platform allows potentially many organic materials to be incorporated into this device to create quantum systems with novel properties. This is due to the fact that precise alignment of the device is not required for light trapping as this critical condition is mainly satisfied by the geometry of the metasurface metal pattern. Interestingly, since scalable fabrication techniques exist to fabricate metasurfaces that interact with terahertz light, we believe that these devices can be used relatively soon for real-world applications of enhanced quantum chemical reactions.

What impact can this research have?

These results bring us closer to the technological ability to capture some of the unique properties of quantum systems consisting of a hybridized state of light and matter.

By conducting a systematic theoretical and experimental study of different types of photonic resonators, we discovered some new photonic resonator designs that can create a quantum superposition between a molecular substance, glucose, and light in a specific region of the far-infrared spectral window called Terahertz region

Previous work has shown that this hybridization process, when involving terahertz light, changes the basic physical and chemical properties of materials. For example, the presence of a photon resonator can change the speed of some chemical reactions related to that substance.

In the future, we believe that this approach can help regulate some molecular processes, leading to applications in medicine for rapid diagnosis and potentially new therapeutic strategies.