Coherent forward scattering peak and multifractality

• Published in: Physical review research Vol. 3; no. 3; p. L032044
• Main Authors: Martinez, Maxime, Lemarié, Gabriel, Georgeot, Bertrand, Miniatura, Christian, Giraud, Olivier
• Format: Journal Article
• Language: English
• Published: American Physical Society 13-08-2021
• Subjects: Nonlinear Sciences; Physics; Quantum Physics
• ISSN: 2643-1564; 2643-1564
• DOI: 10.1103/PhysRevResearch.3.L032044

It has recently been shown that interference effects in disordered systems give rise to two nontrivial structures: the coherent backscattering (CBS) peak, a well-known signature of interference effects in the presence of disorder, and the coherent forward scattering (CFS) peak, which emerges when Anderson localization sets in. We study here the CFS effect in the presence of quantum multifractality, a fundamental property of several systems, such as the Anderson model at the metal-insulator transition. We focus on Floquet systems, and find that the CFS peak shape and its peak height dynamics are generically controlled by the multifractal dimensions D1 and D2, and by the spectral form factor. We check our results using a one-dimensional Floquet system whose states have multifractal properties controlled by a single parameter. Our predictions are fully confirmed by numerical simulations and analytic perturbation expansions on this model. Our results, which we believe to be generic, provide an original and direct way to detect and characterize multifractality in experimental systems.