- Elings 1601
- Soft and Living Matter
The coherent-states quantum field theory for interacting bosons has long provided a convenient mathematical framework for approximate perturbation theory analyses, but numerical sampling of the full field theory has been impeded by the sign problem. By recognizing that the isomorphism between the statistical mechanics of classical polymers and quantum particles extends to the coherent-states field theory representation, algorithms developed for sampling classical polymeric field theories can be adapted for sampling the field theory of assemblies of interacting bosons. We apply the resulting method to map the λ line of critical phase transitions associated with Bose-Einstein condensation in a model φ⁴ field theory. The new approach enjoys near-linear scaling in the resolved (d + 1) spatial / imaginary-time dimensions and should be particularly efficient for the study of dense systems at low temperature.