1. Department of Mathematics and Physics, Università Cattolica del Sacro Cuore, Brescia I-25133, Italy
2. Interdisciplinary Laboratories for Advanced Materials Physics (I-LAMP), Università Cattolica, Brescia I-25133, Italy
3. Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, Leuven 3001, Belgium
4. St. Petersburg State University, St. Petersburg 199034, Russia