Work

Quantum Corrections to the Josephson Dynamics: A Population‐Imbalance Approach

Year: 2026

Type: article

Abstract: ABSTRACT We investigate quantum corrections to the Josephson dynamics of two weakly coupled Bose–Einstein condensates using the population imbalance as the sole dynamical variable. Starting from the two‐variable action, we derive the imbalance‐only Lagrangian with a position‐dependent mass and quantize it via symmetric operator ordering. The leading quantum corrections to the classical potential and mass are computed via the one‐loop quantum effective action, using a covariant background‐field method that fully accounts for the coordinate dependence of the mass. This yields explicit expressions for the effective potential and the effective mass, from which we derive the quantum‐corrected Josephson frequency. Numerical comparison with exact diagonalization of the two‐site Bose–Hubbard model shows that the imbalance‐only formulation performs better than the complementary phase‐only approach in the regime of weak interactions.

Source: Annalen der Physik

DOI: 10.1002/andp.70292

Authors: Oliver Hideg, Sofia Salvatore, Luca Salasnich

Institutions: University of Bonn, University of Padua, Istituto Nazionale di Fisica Nucleare, Sezione di Padova

Language: English

Topic: Cold Atom Physics and Bose-Einstein Condensates

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: Dipartimenti di Eccellenza, European Commission

Awards: G2907606882, G5356239126