The controlled exciton transport of the Multi-chain system by cavity-dressed energy level crossings and anticrossings

TL;DR

This study investigates how cavity-dressed energy level crossings and anticrossings can control exciton transport in multi-chain systems, revealing mechanisms to enhance or suppress transport for designing advanced excitonic devices.

Contribution

It introduces a systematic analysis of exciton transport in multi-chain systems within optical cavities, highlighting the role of cavity-induced energy level crossings and anticrossings in transport control.

Findings

Cavity presence can significantly enhance or suppress exciton transport.

Energy level crossings and anticrossings are key to controlling transport.

Transport efficiency depends on chain length, number, and symmetry, showing oscillatory behavior.

Abstract

The performance of various quantum devices is fundamentally linked to the control of exciton transport. To explore this, we study the exciton transport of the two-dimensional multi-chain systems with different coupling configurations in an optical cavity. Two types of the chains--the homogeneous and heterogeneous coupling chain, as well as two inter-chain coupling conformations--the square and triangular arrangements, are considered. The effects of the inter-chain coupling, the dimerization parameter, the cavity, the length and number of the chains on exciton transport are systematically investigated for different coupling configurations through the spectra, the Hopfield coeffcients, and the steady-state dynamics of the system. The results show that in the absence of a cavity the exciton transport currents and effciency are determined by the exciton distribution across the multi-chain system. However, when a cavity is introduced the exciton transport can be significantly enhanced or suppressed by the polariton formation at the cavity-dressed energy level crossings and anticrossings near zero-energy modes, where the coherent excitation and LandauZener transitions occur. Meanwhile, we discover that the discontinuous and extremal points in the second-order partial derivatives of the photon Hopfield coeffcients with respect to the inter-chain coupling and the dimerization parameter correspond respectively to the crossings and anticrossings at the extreme points of the photon occupation number. Additionally, exciton transport effciency is closely related to the odevity of both chain length and chain number, and exhibits oscillatory behaviour. This work provides critical insights into the exciton transport mechanism in multichain-cavity system and theoretical basis for designing high-erformance excitonic devices with tunable transport properties.