Controlled excitation and resonant acceleration of ultracold few-boson systems by driven interactions in a harmonic trap

TL;DR

This paper explores how time-dependent interactions in a one-dimensional harmonic trap can selectively excite and accelerate ultracold bosonic systems, revealing resonance-driven mechanisms and finite-size effects.

Contribution

It introduces a method to control excitations in few-boson systems via driven interactions, providing detailed analysis of resonance effects and finite-size corrections.

Findings

Selective excitation of collective modes near resonances

Resonance-driven acceleration of bosonic systems

Finite-size effects influence collective oscillations

Abstract

We investigate the excitation properties of finite utracold bosonic systems in a one-dimensional harmonic trap with a time-dependent interaction strength. The driving of the interatomic coupling induces excitations of the relative motion exclusively with specific and controllable contributions of momentarily excited many-body states. Mechanisms for selective excitation to few-body analogues of collective modes and acceleration occur in the vicinity of resonances. We study via the few-body spectrum and a Floquet analysis the excitation mechanisms, and the corresponding impact of the driving frequency and strength as well as the initial correlation of the bosonic state. The fundamental case of two atoms is analyzed in detail and forms a key ingredient for the bottom-up understanding of cases with higher atom numbers, thereby examining finite-size corrections to macroscopic collective modes of oscillation.