Exciton-Polariton Dynamics in Multilayered Materials (2502.12933v1)

Abstract: Coupling excitons with quantized radiation has been shown to enable coherent ballistic transport at room temperature inside optical cavities. Previous theoretical works employ a simple description of the material, depicting it as a single layer placed in the middle of the optical cavity, thereby ignoring the spatial variation of the radiation in the cavity quantization direction. In contrast, in most experiments, the optical cavity is filled with organic molecules or multilayered materials. Here, we develop an efficient mixed-quantum-classical approach, introducing a {\it bright layer} description, to simulate the exciton-polariton quantum dynamics. Our simulations reveal that, for the same Rabi splitting, a multilayer material extends the quantum coherence lifetime and enhances transport compared to a single-layer material. We find that this enhanced coherence can be traced to a synchronization of phonon fluctuations over multiple layers, wherein the collective light-matter coupling in a multilayered material effectively suppresses the phonon-induced dynamical disorder.

Exciton-Polariton Dynamics in Multilayered Materials

The paper of exciton-polariton dynamics within multilayered materials presents a promising pathway to enhancing quantum coherence and transport within optical cavities. This paper introduces a novel mixed quantum-classical approach to simulate these dynamics, emphasizing the role of multilayered configurations in contrast to traditionally modeled single-layer systems.

Key Findings

Simulations reveal that the inclusion of multiple layers significantly extends the coherence lifetime of exciton-polaritons compared to a single layer for the same Rabi splitting. This extended coherence is attributed to a phonon fluctuation synchronization effect across multiple layers, effectively mitigating the influence of phonon-induced disorder.

Theoretical Contributions

To explore exciton-polariton dynamics, the authors develop a mixed quantum-classical method grounded in a bright layer description, achieving computational efficiency in simulating systems with extensive quantum states. This method addresses the challenge of simulating quantum dynamics in systems with a material basis size exceeding $10^6$ states, typical in experiments with $10^2$ layers.

The authors construct a Hamiltonian framework beyond the long-wavelength approximation, incorporating excitonic, phononic, photonic, and their interaction terms, with a focus on exciton-phonon and exciton-cavity interactions. Their model accounts for the distinct band structures encountered in single-layer versus multilayer setups, where multilayer configurations feature numerous optically dark bands altering the density of states near energy levels.

Numerical Simulations and Results

Simulations demonstrate that a multilayer configuration promotes coherent transport, with exciton-polaritons achieving group velocities up to 50% higher than in single-layered materials. This enhancement is directly linked to reduced phonon fluctuation due to the collective interactions within the bright layer span across layers, effectively averaging out the disorder induced by phonons.

Furthermore, when cavity loss is introduced, the paper finds that while overall coherence is reduced, multilayered material systems still show significant improvement over single-layered systems.

Practical and Theoretical Implications

This research highlights the potential of multilayered materials in designing next-generation polaritonic devices, leveraging their ability to maintain extended coherence times and enhanced transport properties. The insights into phonon fluctuation synchronization could inform the architectural design of quantum devices, facilitating operations at macro-scales where quantum coherence is traditionally challenging to sustain.

The paper opens avenues for further investigation into the optimization of light-matter interactions within complex structures, potentially leading to breakthroughs in the development of efficient quantum-based technologies.

Future Directions

Future research could aim to explore the interplay between light-matter coupling strength, phonon interactions, and multilayer variations to fine-tune coherence lifetimes further. The exploration of other material systems, including those with varying phononic environments or alternative cavity setups, could provide a comprehensive perspective on the universality of these findings.

In conclusion, the application of multilayered configurations stands as a significant advancement in the paper of exciton-polariton dynamics, presenting practical means to harness quantum effects at room temperature for advanced quantum device applications.