---
res:
  bibo_abstract:
  - "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.@eng"
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Volker
      foaf_name: Karle, Volker
      foaf_surname: Karle
      foaf_workInfoHomepage: http://www.librecat.org/personId=D7C012AE-D7ED-11E9-95E8-1EC5E5697425
    orcid: 0000-0002-6963-0129
  bibo_doi: 10.15479/AT-ISTA-19393
  dct_date: 2025^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/2663-337X
  dct_language: eng
  dct_publisher: Institute of Science and Technology Austria@
  dct_title: Non-equilibrium topological phases with periodically driven molecules
    and quantum rotors@
...