2006/05/02 by Elena Díaz, E. Diaz, F. Domínguez‐Adame +4
Engineering · Physics and Astronomy · #Quantum chaos and dynamical systems #Spectroscopy and Quantum Chemical Studies #Terahertz technology and applications #cond-mat.dis-nn
paper · pdf · doi:10.1103/physrevb.73.174210
published as Phys. Rev. B 73, 174210 (2006) · 8 pages, 6 PostScript figures, to appear in Phys. Rev. B
arxiv created 2006/05/02 · openalex publication_date 2006/05/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
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)\ensuremath∼1∕k^\ensuremathα, \ensuremathα>0. This type of correlation results in a phase of extended states at the band center, provided \ensuremathα is larger than a critical value \ensuremathαc [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. Dom'\inguez-Adame et al., 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.