Efeitos do acoplamento luz-matéria em sistemas quase-desordenados

Abstract

We theoretically investigate the effects of criticality and multifractal states in a onedimensional model with quasi-disorder (namely, the Aubry-André-Harper model) coupled to electromagnetic cavities. We analyze two specific cases of photon frequencies, varying the coupling with the cavity field. Phase transitions were studied through the calculation of the mean and minimum inverse participation ratio, allowing the identification of metallic, fractal, and insulating states. Our numerical results show that the interaction with the optical cavity introduces an intermediate critical phase between the extended and localized phases, significantly altering the model’s traditional phase diagram. Furthermore, we examine the probability distribution of the inverse participation ratio and perform a multifractal analysis to characterize the critical phase, demonstrating the coexistence of extended, localized, and fractal states in this region. This study highlights the essential role of coupling with electromagnetic cavities in modifying critical transport phenomena at the microscopic level.