The Multi-component Correlated Basis Function Method and its Application to Multilayered Dipolar Bose Gases

TL;DR

This paper introduces a multi-component correlated basis function (CBF) method for analyzing the dynamics of bosonic mixtures, demonstrating its effectiveness on layered dipolar Bose gases with strong interlayer coupling.

Contribution

It derives the multi-component CBF method and applies it to layered dipolar Bose gases, revealing how strong coupling simplifies the spectral structure.

Findings

The method accurately predicts excitation energies in correlated bosonic systems.

Strong interlayer coupling results in a dominant single spectral peak.

Application to 8-layer systems shows simplified spectra under strong coupling.

Abstract

We present a method for calculating the dynamics of a bosonic mixture, the multi-component correlated basis function (CBF) method. For single components, CBF results for the excitation energies agree quite well with experimental results, even for highly correlated systems like $^4$He, and recent systematic improvements of CBF achieve perfect agreement. We give a full derivation of multi-component CBF, and apply the method to a dipolar Bose gas cut into two-dimensional layers by a deep optical lattice, with coupling between layers due to the long-ranged dipole-dipole interaction. We consider the case of strong coupling, leading to large positive interlayer correlations. We calculate the spectrum for a system of 8 layers and show that the strong coupling can lead to a simpler spectrum than in the uncoupled case, with a single peak carrying most of the spectral weight.