Year: 2025
Type: article
Abstract: We consider a multi-species mixture of interacting bosons, N1 bosons of mass m1, N2 bosons of mass m2, and N3 bosons of mass m3, in a harmonic trap with frequency ω. The corresponding intra-species interaction strengths are λ11, λ22, and λ33, and the inter-species interaction strengths are λ12, λ13, and λ23. When the shape of all interactions is harmonic, the system corresponds to the generic multi-species harmonic-interaction model, which is exactly solvable. We start by solving the many-particle Hamiltonian and concisely discussing the ground-state wavefunction and energy in explicit forms as functions of all parameters, the masses, numbers of particles, and the intra-species and inter-species interaction strengths. We then explicitly compute the reduced one-particle density matrices for all the species and diagonalize them, thus generalizing the treatment by the authors earlier. The respective eigenvalues determine the degree of fragmentation of each species. As an application, we focus on phenomena that do not arise in the corresponding single-species or two-species systems. For instance, we consider a mixture of two kinds of bosons in a bath made by a third kind, controlling the fragmentation of the former by coupling to the latter. Another example exploits the possibility of different connectivities (i.e., which species interacts with which species) in the mixture, and demonstrates how the fragmentation of species 3 can be manipulated by the interaction between species 1 and species 2, when species 3 and 1 do not interact with each other. We highlight the properties of fragmentation that only appear in the multi-species mixture. Further applications are briefly discussed.
Source: Physics
Authors: Ofir E. Alon, Lorenz S. Cederbaum
Institutions: University of Haifa, Heidelberg University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,689
Funder: Israel Science Foundation
Award: G5658896161
OpenAlex ID: W4413908458
