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oai:docta.ucm.es:20.500.14352/512492023-08-27T19:22:35Zcom_20.500.14352_14col_20.500.14352_15

Díaz García, Elena Domínguez-Adame Acosta, Francisco Kosevich, Yu Malyshev, Andrey 2023-06-20T10:48:08Z 2023-06-20T10:48:08Z 2006-05 1098-0121 10.1103/PhysRevB.73.174210 https://hdl.handle.net/20.500.14352/51249 http://dx.doi.org/10.1103/PhysRevB.73.174210 http://journals.aps.org/ We study numerically the linear optical response of a quasiparticle moving on a one-dimensional disordered lattice in the presence of a linear bias. The random site potential is assumed to be long-range correlated with a power-law spectral density S(k)similar to 1/k(alpha), alpha > 0. This type of correlation results in a phase of extended states at the band center, provided alpha is larger than a critical value alpha(c) [F. A. B. F. de Moura and M. L. Lyra, Phys. Rev. Lett. 81, 3735 (1998)]. The width of the delocalized phase can be tested by applying an external electric field: Bloch-like oscillations of a quasiparticle wave packet are governed by the two mobility edges, playing now the role of band edges [F. Dominguez-Adame , Phys. Rev. Lett. 91, 197402 (2003)]. We demonstrate that the frequency-domain counterpart of these oscillations, the so-called Wannier-Stark ladder, also arises in this system. When the phase of extended states emerges in the system, this ladder turns out to be a comb of doublets, for some range of disorder strength and bias. Linear optical absorption provides a tool to detect this level structure. eng open access Wannier-Stark ladder in the linear absorption of a random system with scale-free disorder journal article