Phonons are energy waves that travel through crystal lattices via atomic vibrations. Often compared to ripples in a pond, phonons play a vital role in optoelectronic applications and tunable photonic devices.
Scientists have long sought ways to regulate these vibrations, and IISc’s latest study presents a promising approach.
A team of researchers at the Indian Institute of Science (IISc) has uncovered a groundbreaking method for controlling the properties of phonons by manipulating twist angles in two-dimensional materials.
The study highlights how varying twist angles between layers of WSe₂ (Tungsten Diselenide) homobilayers impact phonon hybridization and electronic interactions.
The team employed Raman spectroscopy to demonstrate that twist angles between 1° and 7° induce phonon mode splitting. They also observed temperature-driven shifts in Raman frequencies at low temperatures (below 50 K). This highlights the interplay of electron-phonon coupling and phonon anharmonicity in twisted systems.
This breakthrough can help engineers engineer materials with tailored thermal, optical, and electronic characteristics, which are vital for quantum technology.
Journal Reference:
- Krishna Prasad Bera, Darshit Solanki, Shinjan Mandal, Rabindra Biswas, Takashi Taniguchi, Kenji Watanabe, Varun Raghunathan, Manish JainA. K. Sood and Anindya Das. Twist Angle-Dependent Phonon Hybridization in WSe2/WSe2 Homobilayer. ACS Nano. DOI: 10.1021/acsnano.4c06767
