Rotation of Quantum Impurities in the Presence of a Many-Body Environment.

  title={Rotation of Quantum Impurities in the Presence of a Many-Body Environment.},
  author={Richard Schmidt and Mikhail Lemeshko},
  journal={Physical review letters},
  volume={114 20},
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… 

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