Thursday 17 April 2025
In a breakthrough discovery, scientists have found that circularly polarized light can induce angular rotation in molecules that possess coupled doubly degenerate electronic orbitals and chiral normal modes. This phenomenon is a result of an e × E Jahn-Teller effect, where the molecular structure itself plays a crucial role in the interaction between the light and the molecule.
The researchers created two exemplary models to demonstrate this effect: an ionic molecule with D3 symmetry, inspired by metal trifluorides, and a covalent molecule with D6 symmetry, inspired by benzene. They found that regardless of whether the molecular structure is ionic or covalent, the chiral normal modes can be excited independently, leading to the rotation of the entire molecule.
The study’s findings have significant implications for our understanding of the interaction between light and matter at a molecular level. The researchers demonstrated that the angular momentum carried by the chiral phonons in the molecule is conserved, meaning that it remains unchanged during the interaction with the light.
This conservation of angular momentum leads to an interesting phenomenon: even if the initial direction of rotation is randomly distributed, the final state of the molecule’s rotation will be determined by the handedness of the chiral normal modes. This means that the light can drive the sample into rotation, inducing a finite angular velocity.
The study also highlights the potential for controlling molecular rotations using circularly polarized light. By tuning the frequency and polarization of the light, scientists may be able to manipulate the direction and magnitude of the molecule’s rotation.
Moreover, this research sheds light on the fundamental nature of chiral phonons in solids and their role in determining the macroscopic properties of materials. Chiral phonons have been predicted to exist in certain crystals, but their observation has remained elusive. This study provides a framework for understanding how chiral phonons interact with light and matter.
The discovery of this phenomenon has significant implications for various fields, including quantum computing, optoelectronics, and biophysics. The ability to control molecular rotations using circularly polarized light could lead to new methods for data storage, information processing, and even the development of novel biomedical tools.
As scientists continue to explore the mysteries of light-matter interactions at a molecular level, this study provides a fascinating glimpse into the intricate dance between photons and matter.
Cite this article: “Light Can Make Molecules Spin: Unlocking the Secrets of Chiral Phonons”, The Science Archive, 2025.
Circularly Polarized Light, Molecular Rotation, Jahn-Teller Effect, Chiral Normal Modes, Angular Momentum, Phonons, Quantum Computing, Optoelectronics, Biophysics, Chiral Solids
