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… 

Figures from this paper

Deformation of a quantum many-particle system by a rotating impurity
During the last 70 years, the quantum theory of angular momentum has been successfully applied to describing the properties of nuclei, atoms, and molecules, their interactions with each other as well
Theory of the rotating polaron: Spectrum and self-localization
We study a quantum impurity possessing both translational and internal rotational degrees of freedom interacting with a bosonic bath. Such a system corresponds to a “rotating polaron,” which can be
Anyonic statistics of quantum impurities in two dimensions
We demonstrate that identical impurities immersed in a two-dimensional many-particle bath can be viewed as flux-tube-charged-particle composites described by fractional statistics. In particular, we
A New Angle on Quantum Impurities Quasiparticles called angulons can simplify the theoretical description of a molecule immersed in a quantum solvent
U nderstanding how impurities interact with a quantum environment is an important problem with widespread implications in physics [1, 2]. An impurity has complex quantum-mechanical interactions with
Diagrammatic Monte Carlo Approach to Angular Momentum in Quantum Many-Particle Systems.
A diagrammatic Monte Carlo approach to angular momentum properties of quantum many-particle systems possessing a macroscopic number of degrees of freedom is introduced, applicable at arbitrary coupling, is free of systematic errors and of finite-size effects, and naturally provides access to the impurity Green function.
Quantum Particle in a Magnetic Environment
In this Chapter, we study yet another fundamental paradigm of a quantum impurity, a mobile spinless particle interacting with a many-particle environment. The ultimate building block of such a system
Microscopic Derivation of the Fröhlich Hamiltonian for the Bose Polaron in the Mean-Field Limit
We consider the quantum mechanical many-body problem of a single particle immersed in a weakly interacting Bose gas. The impurity interacts with the bosons via a two-body potential. We study the
Quantum impurity model for anyons
One of the hallmarks of quantum statistics, tightly entwined with the concept of topological phases of matter, is the prediction of anyons. Although anyons are predicted to be realized in certain
Quantum many-body dynamics of the Einstein–de Haas effect
In 1915, Einstein and de Haas and Barnett demonstrated that changing the magnetization of a magnetic material results in mechanical rotation and vice versa. At the microscopic level, this effect
Bose polaron in spherical trap potentials: Spatial structure and quantum depletion
We investigate how the presence of a localized impurity in a Bose-Einstein condensate of trapped cold atoms that interact with each other weakly and repulsively affects the profile of the condensed


Deformation of a quantum many-particle system by a rotating impurity
During the last 70 years, the quantum theory of angular momentum has been successfully applied to describing the properties of nuclei, atoms, and molecules, their interactions with each other as well
Feynman path-integral treatment of the BEC-impurity polaron
The description of an impurity atom in a Bose-Einstein condensate can be cast in the form of Frohlich's polaron Hamiltonian, where the Bogoliubov excitations play the role of the phonons. An
Field-theoretical study of the Bose polaron
We study the properties of the Bose polaron, an impurity strongly interacting with a Bose-Einstein condensate, using a field-theoretic approach and make predictions for the spectral function and
Strong-coupling theory for the superfluidity of Bose-Fermi mixtures.
A strong-coupling theory for the superfluidity of fermion pairing phase in a Bose-Fermi mixture is developed and it is found that the calculated T(c) is several times larger than that obtained in the weak coupling theory, and can be up to several percent of the Fermi temperature.
Quantum phase transitions
Abstract We give a general introduction to quantum phase transitions in strongly correlated electron systems. These transitions, which occur at zero temperature when a non-thermal parameter g such as
Radio-frequency spectroscopy of polarons in ultracold Bose gases
Recent experimental advances enabled the realization of mobile impurities immersed in a Bose-Einstein condensate (BEC) of ultracold atoms. Here we consider impurities with two or more internal
Quantum rotation of HCN and DCN in 4 He
We present calculations of rotational absorption spectra of the molecules HCN and DCN in superfluid 4 He, using a combination of the diffusion Monte Carlo method for ground-state properties and an
The Holstein Polaron
We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to
Repulsively bound atom pairs in an optical lattice
These results exemplify the strong correspondence between the optical lattice physics of ultracold bosonic atoms and the Bose–Hubbard model—a link that is vital for future applications of these systems to the study of strongly correlated condensed matter and to quantum information.