Wentzel-Kramers-Brillouin approach and quantum corrections to classical dynamics in the Josephson problem

Felix Nissen; Jonathan Keeling

doi:10.1103/PhysRevA.81.063628

← Back to search

Wentzel-Kramers-Brillouin approach and quantum corrections to classical dynamics in the Josephson problem

Felix Nissen, Jonathan Keeling

DOI 10.1103/PhysRevA.81.063628 · Physical Review A

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We apply a many-body Wentzel-Kramers-Brillouin (WKB) approach to determine the leading quantum corrections to the semiclassical dynamics of the Josephson model, describing interacting bosons able to tunnel between two localized states. The semiclassical dynamics is known to divide between regular oscillations and self-trapped oscillations where the sign of the imbalance remains fixed. In both cases, the WKB wave functions are matched to Airy functions, yielding a modified Bohr-Sommerfeld quantization condition. At the critical energy dividing normal and self-trapped oscillations, the WKB wave functions should instead be matched to parabolic cylinder functions, leading to a quantization formula that is not just the Bohr-Sommerfeld formula, and recovering the known logarithmic quantum break times at this energy. This work thus provides another illustration of the usefulness of the WKB approach in certain many-body problems.