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Coupled Electron-Phonon Hydrodynamics in Two-Dimensional Semiconductors
1University of California, Department of Mechanical Engineering, Santa Barbara, California 93106, USA.
Physical Review Letters
|June 23, 2025
Summary
Momentum circulation between electrons and phonons enables low-dissipation transport in two-dimensional (2D) semiconductors. This electron-phonon hydrodynamic regime enhances carrier mobility, challenging previous assumptions about strong interactions limiting performance.
Area of Science:
- Condensed Matter Physics
- Materials Science
Background:
- Electron-phonon interactions are crucial for charge transport in 2D semiconductors.
- These interactions typically limit carrier mobility at higher temperatures.
- Understanding these dynamics is key for advancing semiconductor miniaturization.
Purpose of the Study:
- To investigate momentum circulation between electrons and phonons in 2D semiconductors.
- To determine the impact of this circulation on carrier transport properties.
- To explore the possibility of low-dissipation transport despite strong electron-phonon coupling.
Main Methods:
- Systematic investigation of momentum circulation dynamics.
- Analysis of coupled electron-phonon systems.
- Theoretical modeling of transport properties in 2D semiconductors.
Main Results:
- Strong momentum circulation leads to weak dissipation in the coupled electron-phonon system.
- A coupled electron-phonon hydrodynamic transport regime emerges with joint electron-phonon drift.
- Charge transport properties are significantly enhanced in this regime.
Conclusions:
- Low-dissipation charge transport is achievable even with strong electron-phonon interactions.
- Effective momentum circulation is key to overcoming mobility limitations.
- This work advances the fundamental understanding of carrier transport in 2D materials.
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