Rotation of Quantum Impurities in the Presence of a Many-Body Environment
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.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 2015
- DOI:
- 10.1103/PhysRevLett.114.203001
- arXiv:
- arXiv:1502.03447
- Bibcode:
- 2015PhRvL.114t3001S
- Keywords:
-
- 33.20.Sn;
- 34.90.+q;
- 67.90.+z;
- 72.10.Di;
- Rotational analysis;
- Other topics in atomic and molecular collision processes and interactions;
- Other topics in quantum fluids and solids;
- liquid and solid helium;
- Scattering by phonons magnons and other nonlocalized excitations;
- Condensed Matter - Quantum Gases;
- Physics - Atomic and Molecular Clusters;
- Physics - Atomic Physics;
- Physics - Chemical Physics;
- Quantum Physics
- E-Print:
- 5 pages, 2 figures