New Delhi: A groundbreaking study led by researchers at the Indian Institute of Science (IISc), Bangalore, has introduced a novel method to control the properties of phonons, which could be pivotal for the development of engineering materials essential for emerging quantum technologies.

Phonons, which are energy waves traveling through a crystal lattice when atoms vibrate, are fundamental to the thermal, optical, and electronic characteristics of materials. By adjusting twist angles between layers of two-dimensional (2D) materials, scientists can manipulate phonon behavior to design materials with customized properties for use in quantum technology.

The research, published in ACS Nano, explores how varying twist angles in WSe2 (Tungsten diselenide) homobilayers influence phonon hybridization. This work reveals the impact of moiré superstructures, formed when two or more 2D lattices overlap, on phononic and electronic interactions. The team utilized Raman spectroscopy to study the effects of twist angles between 1° and 7°, observing that they induce splitting in phonon modes.

Significant findings include temperature-driven shifts in Raman frequencies and line widths at low temperatures (below 50 K), highlighting the complex interplay of electron-phonon coupling and phonon anharmonicity in twisted systems. These insights open new avenues for the design of materials suited for photonic, quantum, and electronic applications.

This research was supported by the Department of Science and Technology (DST) under the FIST (Fund for Improvement of Science and Technology Infrastructure) program, marking a key step in the advancement of quantum materials engineering.