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Gate-tunable chiral phonons in low-buckled group-IVA monolayers
Hanyu Wang1,2, Zhichao Zhou1, Hao Chen1,2
1School of Physics and Technology, Nanjing Normal University, Nanjing 210023, People's Republic of China.
Summary
We demonstrate electric field control of chiral phonons in group-IVA monolayers. Applying a vertical electric field creates a tunable phononic gap with chiral properties, useful for phononic and valleytronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Chiral phonons exhibit unique properties related to their polarization and angular momentum.
- Low-buckled group-IVA monolayers are a class of 2D materials with potential for novel electronic and phononic applications.
Purpose of the Study:
- To investigate the electric response of chiral phonons in low-buckled group-IVA monolayers.
- To explore the possibility of controlling phonon chirality using external electric fields.
Main Methods:
- First-principles calculations were employed to simulate the behavior of phonons.
- The effect of a vertical electric field on phonon modes at high-symmetry points (±K) was analyzed.
Main Results:
- A vertical electric field breaks phonon mode degeneracy, creating a tunable phononic gap.
- The gapped phonon modes at ±K exhibit chirality, characterized by circular polarization and pseudoangular momentum.
- Phonon chirality is robust to field strength variations but reverses with field direction.
Conclusions:
- Electric control of chiral phonons is achievable in group-IVA monolayers.
- This electric tunability offers new avenues for designing advanced phononic and valleytronic devices.
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