Fingerprints of angulon instabilities in the spectra of matrix-isolated molecules Journal Article


Author(s): Cherepanov, Igor N; Lemeshko, Mikhail
Article Title: Fingerprints of angulon instabilities in the spectra of matrix-isolated molecules
Affiliation IST Austria
Abstract: The formation of vortices is usually considered to be the main mechanism of angular momentum disposal in superfluids. Recently, it was predicted that a superfluid can acquire angular momentum via an alternative, microscopic route -- namely, through interaction with rotating impurities, forming so-called `angulon quasiparticles' [Phys. Rev. Lett. 114, 203001 (2015)]. The angulon instabilities correspond to transfer of a small number of angular momentum quanta from the impurity to the superfluid, as opposed to vortex instabilities, where angular momentum is quantized in units of ℏ per atom. Furthermore, since conventional impurities (such as molecules) represent three-dimensional (3D) rotors, the angular momentum transferred is intrinsically 3D as well, as opposed to a merely planar rotation which is inherent to vortices. Herein we show that the angulon theory can explain the anomalous broadening of the spectroscopic lines observed for CH 3 and NH 3 molecules in superfluid helium nanodroplets, thereby providing a fingerprint of the emerging angulon instabilities in experiment.
Keywords: Quantum Gases (cond-mat.quant-gas); Chemical Physics (physics.chem-ph); Atomic and Molecular Clusters (physics.atm-clus)
Journal Title: Physical Review Materials
Volume: 1
Issue 3
ISSN: 2475-9953
Publisher: APS Physics  
Date Published: 2017-08-08
Start Page: Article number: 035602
URL:
DOI: 10.1103/PhysRevMaterials.1.035602
Open access: yes (repository)