Diagrammatic Monte Carlo Approach to Angular Momentum in Quantum Many-Particle Systems

G. Bighin, T. V. Tscherbul, and M. Lemeshko

Phys. Rev. Lett. 121, 165301 – Published 16 October 2018

Abstract

We introduce a diagrammatic Monte Carlo approach to angular momentum properties of quantum many-particle systems possessing a macroscopic number of degrees of freedom. The treatment is based on a diagrammatic expansion that merges the usual Feynman diagrams with the angular momentum diagrams known from atomic and nuclear structure theory, thereby incorporating the non-Abelian algebra inherent to quantum rotations. Our approach is applicable at arbitrary coupling, is free of systematic errors and of finite-size effects, and naturally provides access to the impurity Green function. We exemplify the technique by obtaining an all-coupling solution of the angulon model; however, the method is quite general and can be applied to a broad variety of systems in which particles exchange quantum angular momentum with their many-body environment.

Received 21 March 2018
Revised 1 July 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.165301

Physics Subject Headings (PhySH)

Feynman diagrams Impurities

Bose-Einstein condensates Molecules

Diagrammatic methods Green's function methods Quantum Monte Carlo

Atomic, Molecular & OpticalCondensed Matter, Materials & Applied Physics

Authors & Affiliations

G. Bighin¹, T. V. Tscherbul², and M. Lemeshko¹

¹IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
²Department of Physics, University of Nevada, Reno, Nevada 89557, USA