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Abstract Excitons are elementary optical excitation in semiconductors. The ability to manipulate and transport these quasiparticles would enable excitonic circuits and devices for quantum photonic technologies. Recently, interlayer excitons in 2D semiconductors have emerged as a promising candidate for engineering excitonic devices due to their long lifetime, large exciton binding energy, and gate tunability. However, the charge-neutral nature of the excitons leads to weak response to the in-plane electric field and thus inhibits transport beyond the diffusion length. Here, we demonstrate the directional transport of interlayer excitons in bilayer WSe2driven by the propagating potential traps induced by surface acoustic waves (SAW). We show that at 100 K, the SAW-driven excitonic transport is activated above a threshold acoustic power and reaches 20 μm, a distance at least ten times longer than the diffusion length and only limited by the device size. Temperature-dependent measurement reveals the transition from the diffusion-limited regime at low temperature to the acoustic field-driven regime at elevated temperature. Our work shows that acoustic waves are an effective, contact-free means to control exciton dynamics and transport, promising for realizing 2D materials-based excitonic devices such as exciton transistors, switches, and transducers up to room temperature.
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This content will become publicly available on May 23, 2026
2D material exciton-polariton transport on 2D photonic crystals
Transport of elementary excitations is a fundamental property of two-dimensional (2D) semiconductors, essential for wide-ranging phenomena and device applications. Although exciton transport reported in 2D materials barely exceeds 1 to 2 micrometers, coherent coupling of excitons with photons to form polaritons enables extended transport lengths and offers opportunities to use photonic mode engineering for tailored transport. Conventional vertical cavity or waveguide polaritons, however, are challenging to tune and integrate into photonic circuits. We report the transport of transition metal dichalcogenide polaritons in 2D photonic crystals that are highly versatile for tuning, mode engineering, and integration. We achieve an order-of-magnitude enhancement in transport length compared to bare excitons and reveal transport dependence on polariton dispersion and population dynamics, which are controlled via photonic crystal design and pump intensity. Stimulated relaxation observed in the system suggests the potential for forming superfluid polaritons with frictionless transport. These findings establish 2D photonic crystal polaritons as a versatile platform for advancing photonic energy transport technologies.
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- Award ID(s):
- 2004287
- PAR ID:
- 10638670
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 11
- Issue:
- 21
- ISSN:
- 2375-2548
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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