--- OA_place: publisher OA_type: gold _id: '19393' abstract: - lang: eng text: "Rotations constitute one of the fundamental symmetries in physics, characterized by their intricate group structure and infinite dimensional representations. In contrast to classical rotations, quantum mechanics unveils the SO(3) symmetry group structure, manifesting in phenomena without classical counterparts, from angular momentum quantization to non-trivial addition of angular momenta.\r\nWhile most studies of topological physics have focused on two-band systems, the SO(3) symmetry group of quantum rotors offers an inherently more complex platform with unprecedented possibilities for exploring topological phenomena. Despite their ubiquity in nature– from molecules to nanorotors– their potential for hosting topological phases has remained largely unexamined.\r\nIn this thesis, we mainly focus on periodically driven linear molecules as a prototype for studying topological phenomena in quantum rotors. Recent technological advances in coherent control of molecules, particularly through precisely shaped laser pulses, have made it possible to investigate linear rotors in the context of topology. While planar rotors have received some attention in recent years, threedimensional rotors–particularly linear molecules–harbor substantially richer topological phenomena due to their non-abelian nature and their additional angular degrees of freedom. We demonstrate that these systems can host novel edge states and topological features fundamentally impossible in planar systems.\r\nWe begin by establishing a theoretical bridge between periodically kicked rotors and \"crystalline\" lattices in angular momentum space. Using non-interacting linear molecules as our primary example, we show how quantum interference and revival patterns lead to the possibility to simulate band models with arbitrary number of bands N. While our framework applies to various quantum rotors, including nanorotors and kicked Bose-Einstein condensates, linear\r\nmolecules provide an ideal experimental platform due to their abovementioned precise controllability.\r\nThe core of this work examines adiabatic dynamics of 3D quantum rotors, establishing a geometric framework based on the Euler class to characterize its non-abelian topology. The non-Hermitian nature of the system enables novel braiding behaviors and topological transitions impossible in static systems, leading to an anomalous Dirac string phase with edge states in each gap, even though the Berry phases are all zero. These features can be directly observed through\r\nmolecular alignment and rotational level populations.\r\nThese findings establish quantum rotors as an alternative platform for studying multi-band topological physics, while suggesting practical implementations for quantum computation where topological protection could offer natural resilience against decoherence. The rich structure of three-dimensional rotation groups, combined with the tunability of topological features through driving parameters, makes this platform particularly valuable for exploring fundamental\r\nphysics and developing quantum technologies." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Volker full_name: Karle, Volker id: D7C012AE-D7ED-11E9-95E8-1EC5E5697425 last_name: Karle orcid: 0000-0002-6963-0129 citation: ama: Karle V. Non-equilibrium topological phases with periodically driven molecules and quantum rotors. 2025. doi:10.15479/AT-ISTA-19393 apa: Karle, V. (2025). Non-equilibrium topological phases with periodically driven molecules and quantum rotors. Institute of Science and Technology Austria. https://doi.org/10.15479/AT-ISTA-19393 chicago: Karle, Volker. “Non-Equilibrium Topological Phases with Periodically Driven Molecules and Quantum Rotors.” Institute of Science and Technology Austria, 2025. https://doi.org/10.15479/AT-ISTA-19393. ieee: V. Karle, “Non-equilibrium topological phases with periodically driven molecules and quantum rotors,” Institute of Science and Technology Austria, 2025. ista: Karle V. 2025. Non-equilibrium topological phases with periodically driven molecules and quantum rotors. Institute of Science and Technology Austria. mla: Karle, Volker. Non-Equilibrium Topological Phases with Periodically Driven Molecules and Quantum Rotors. Institute of Science and Technology Austria, 2025, doi:10.15479/AT-ISTA-19393. short: V. Karle, Non-Equilibrium Topological Phases with Periodically Driven Molecules and Quantum Rotors, Institute of Science and Technology Austria, 2025. corr_author: '1' date_created: 2025-03-12T13:04:59Z date_published: 2025-03-13T00:00:00Z date_updated: 2025-09-04T12:04:20Z day: '13' ddc: - '530' degree_awarded: PhD department: - _id: GradSch - _id: MiLe doi: 10.15479/AT-ISTA-19393 file: - access_level: open_access checksum: d3ab25782c7ea38ce9910e57d25f6733 content_type: application/pdf creator: vkarle date_created: 2025-03-12T12:56:46Z date_updated: 2025-03-12T12:56:46Z file_id: '19394' file_name: thesis_final.pdf file_size: 10625143 relation: main_file success: 1 - access_level: closed checksum: 3ccfb0aeba4d860d71e18347913034e4 content_type: application/zip creator: vkarle date_created: 2025-03-13T13:15:10Z date_updated: 2025-03-20T08:02:35Z file_id: '19400' file_name: thesis.zip file_size: 23119202 relation: source_file file_date_updated: 2025-03-20T08:02:35Z has_accepted_license: '1' language: - iso: eng month: '03' oa: 1 oa_version: Published Version page: '192' publication_identifier: eissn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '14851' relation: part_of_dissertation status: public - id: '12788' relation: part_of_dissertation status: public - id: '19425' relation: part_of_dissertation status: public - id: '9903' relation: part_of_dissertation status: public - id: '15004' relation: part_of_dissertation status: public status: public supervisor: - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 title: Non-equilibrium topological phases with periodically driven molecules and quantum rotors tmp: image: /images/cc_by_nc_nd.png legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) short: CC BY-NC-ND (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2025' ...