@article{1813,
  abstract     = {We develop a microscopic theory describing a quantum impurity whose rotational degree of freedom is coupled to a many-particle bath. We approach the problem by introducing the concept of an “angulon”—a quantum rotor dressed by a quantum field—and reveal its quasiparticle properties using a combination of variational and diagrammatic techniques. Our theory predicts renormalization of the impurity rotational structure, such as that observed in experiments with molecules in superfluid helium droplets, in terms of a rotational Lamb shift induced by the many-particle environment. Furthermore, we discover a rich many-body-induced fine structure, emerging in rotational spectra due to a redistribution of angular momentum within the quantum many-body system.},
  author       = {Schmidt, Richard and Lemeshko, Mikhail},
  journal      = {Physical Review Letters},
  number       = {20},
  publisher    = {American Physical Society},
  title        = {{Rotation of quantum impurities in the presence of a many-body environment}},
  doi          = {10.1103/PhysRevLett.114.203001},
  volume       = {114},
  year         = {2015},
}