Three atoms in a tight spot

Marsden project 20-MAU-028 funded 2021 - 2024
Principal investigator: Joachim Brand
Associate investigator: Mikkel Anderson

(From APS Physics: Watching three atoms collide)

When three cold atoms are brought into close proximity, they may collide and form a molecule, or keep their distance. Can we understand the rules of potentially chaotic motion in such atomic triads? Is it possible to manipulate the atoms in a way that they never meet, and molecule formation is suppressed? We now have unprecedented capabilities to assemble, manipulate, and observe three-atom systems in optical tweezer traps at the single event level, but are still lacking theoretical insight. Motivated by unexplained experimental data and building on our recent success in reducing the complexity of quantum simulations with the transcorrelated method for ultra-cold atoms, we will develop new simulation tools to aid our understanding of few atom dynamics in optical tweezers accounting for realistic experimental conditions.
Existing theory for idealised triads predicts regular motion and extremely long-lived quantum states with suppressed molecule formation rates. The purpose of this project is to understand in how far this prediction holds up under realistic conditions. How can an expected transition to quantum chaos be monitored and manipulated or mitigated while building up correlated phases of matter, atom by atom? Our theoretical predictions will be tested in experiments with ultra-cold atoms in optical tweezers.

During the course of this project we will investigate the semiclassical dynamics of three atoms in a tightly confined trap. This will be complemented by a computational study of three-boson quantum states. We will make use of and extend the software package Rimu.jl to study this problem using deterministic and stochastic (quantum Monte Carlo) algorithms.

We are hiring!

• Postdoctocal Fellow in Theoretical and Computational Physics (Application deadline 1 September 2021)
  Job details on UCAN.
  Job details on Massey Careers site: Apply here! Job reference: CS_NZIAS_1027_07/21
• Funded PhD project in few-atom dynamics

For further information please contact Joachim directly.

See also:

• Reynolds et al., Direct Measurements of Collisional Dynamics in Cold Atom Triads, Phys. Rev. Lett. 124, 073401 (2020), [arXiv]
• Jeszenszki et al., Eliminating the wave-function singularity for ultracold atoms by a similarity transformation, Phys. Rev. Research 2, 043270 (2020)

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