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Description
The optical conductivity in a wide variety of correlated models has been shown to be dominated by pi-ton vertex corrections, which describe the coupling of light with antiferromagnetic or charge density wave fluctuations with a wave vector close to q = (pi, pi, ...) [1]. While the analysis [2] of the pi-ton vertex corrections in two-dimensional (2D) weakly correlated systems show that they generally lead to a temperature-dependent broadening/sharpening of a Drude peak, it has been pointed out in [3] and [4] that in one-dimensional (1D) systems an additional pi-ton peak between the Drude and the high-frequency features may appear. However, in the latter work, analytical continuation was necessary in the final step to obtain the real frequency optical spectra, which makes the analysis of fine spectral features a bit cumbersome. Therefore, here we semianalytically study the pi-tons on a level of a random phase approximation ladder in the transversal particle-hole channel, analogous to the approach in [2], to differentiate and identify their characteristic features in weakly correlated 1D and 2D systems. Our results show that in 1D systems, the pi-ton vertex corrections are indeed way stronger than in 2D systems, leading to features beyond the simple renormalization of the Drude peak.
References:
[1] A. Kauch et al., Phys. Rev. Lett. 124, 047401 (2020).
[2] P. Worm et al., Phys. Rev. B 104, 115153 (2021).
[3] O. Simard et al., Phys. Rev. B 104, 245127 (2021).
[4] O. Simard et al., Phys. Rev. B 103, 104415 (2021).
