TY - JOUR AB - We study an impurity with a resonance level whose position coincides with the Fermi energy of the surrounding Fermi gas. An impurity causes a rapid variation of the scattering phase shift for fermions at the Fermi surface, introducing a new characteristic length scale into the problem. We investigate manifestations of this length scale in the self-energy of the impurity and in the density of the bath. Our calculations reveal a model-independent deformation of the density of the Fermi gas, which is determined by the width of the resonance. To provide a broader picture, we investigate time evolution of the density in quench dynamics, and study the behavior of the system at finite temperatures. Finally, we briefly discuss implications of our findings for the Fermi-polaron problem. AU - Maslov, Mikhail AU - Lemeshko, Mikhail AU - Volosniev, Artem ID - 10845 JF - Physical Review Research SN - 2643-1564 TI - Impurity with a resonance in the vicinity of the Fermi energy VL - 4 ER - TY - GEN AB - The main idea behind the Core Project is to teach first year students at IST scientific communication skills and let them practice by presenting their research within an interdisciplinary environment. Over the course of the first semester, students participated in seminars, where they shared their results with the colleagues from other fields and took part in discussions on relevant subjects. The main focus during this sessions was on delivering the information in a simplified and comprehensible way, going into the very basics of a subject if necessary. At the end, the students were asked to present their research in the written form to exercise their writing skills. The reports were gathered in this document. All of them were reviewed by the teaching assistants and write-ups illustrating unique stylistic features and, in general, an outstanding level of writing skills, were honorably mentioned in the section "Selected Reports". AU - Maslov, Mikhail AU - Kondrashov, Fyodor AU - Artner, Christina AU - Hennessey-Wesen, Mike AU - Kavcic, Bor AU - Machnik, Nick N AU - Satapathy, Roshan K AU - Tomanek, Isabella ID - 8151 TI - Core Project Proceedings ER - TY - JOUR AB - We study a mobile quantum impurity, possessing internal rotational degrees of freedom, confined to a ring in the presence of a many-particle bosonic bath. By considering the recently introduced rotating polaron problem, we define the Hamiltonian and examine the energy spectrum. The weak-coupling regime is studied by means of a variational ansatz in the truncated Fock space. The corresponding spectrum indicates that there emerges a coupling between the internal and orbital angular momenta of the impurity as a consequence of the phonon exchange. We interpret the coupling as a phonon-mediated spin-orbit coupling and quantify it by using a correlation function between the internal and the orbital angular momentum operators. The strong-coupling regime is investigated within the Pekar approach, and it is shown that the correlation function of the ground state shows a kink at a critical coupling, that is explained by a sharp transition from the noninteracting state to the states that exhibit strong interaction with the surroundings. The results might find applications in such fields as spintronics or topological insulators where spin-orbit coupling is of crucial importance. AU - Maslov, Mikhail AU - Lemeshko, Mikhail AU - Yakaboylu, Enderalp ID - 7933 IS - 18 JF - Physical Review B SN - 24699950 TI - Synthetic spin-orbit coupling mediated by a bosonic environment VL - 101 ER - TY - JOUR AB - Focused ion beams perfectly suit for patterning two-dimensional (2D) materials, but the optimization of irradiation parameters requires full microscopic understanding of defect production mechanisms. In contrast to freestanding 2D systems, the details of damage creation in supported 2D materials are not fully understood, whereas the majority of experiments have been carried out for 2D targets deposited on substrates. Here, we suggest a universal and computationally efficient scheme to model the irradiation of supported 2D materials, which combines analytical potential molecular dynamics with Monte Carlo simulations and makes it possible to independently assess the contributions to the damage from backscattered ions and atoms sputtered from the substrate. Using the scheme, we study the defect production in graphene and MoS2 sheets, which are the two most important and wide-spread 2D materials, deposited on a SiO2 substrate. For helium and neon ions with a wide range of initial ion energies including those used in a commercial helium ion microscope (HIM), we demonstrate that depending on the ion energy and mass, the defect production in 2D systems can be dominated by backscattered ions and sputtered substrate atoms rather than by the direct ion impacts and that the amount of damage in 2D materials heavily depends on whether a substrate is present or not. We also study the factors which limit the spatial resolution of the patterning process. Our results, which agree well with the available experimental data, provide not only insights into defect production but also quantitative information, which can be used for the minimization of damage during imaging in HIM or optimization of the patterning process. AU - Kretschmer, Silvan AU - Maslov, Mikhail AU - Ghaderzadeh, Sadegh AU - Ghorbani-Asl, Mahdi AU - Hlawacek, Gregor AU - Krasheninnikov, Arkady V. ID - 13255 IS - 36 JF - ACS Applied Materials & Interfaces KW - General Materials Science SN - 1944-8244 TI - Supported two-dimensional materials under ion irradiation: The substrate governs defect production VL - 10 ER -