# Collaborations

## D. Wilkowski (NTU, Singapore)

WIth D. Wilkowski, from NTU at Singapore, we recently explores the physics of ultracold atoms in non-abelian gauge fields. We have shown that a uniform non-Abelian field would lead to a terembling motion of a free particle that could be observed and characterized experimentally on NTU's strontium machine.

Anisotropic Zitterbewegung Dynamics in Synthetic Non-Abelian Gauge Fields, M. Hasan, C.S. Madasu, K.D. Rathod, C.C. Kwong, C. Miniatura, F Chevy, D. Wilkowski, PRL 129, 130402 (2022)

Non-Abelian adiabatic geometric transformations in a cold strontium gas, F. Leroux, K. Pandey, R. Rehbi, F. Chevy, C. Miniatura, B. Grémaud, D. Wilkowski, Nature communications 9 (1), 1-7 (2018)

## J.H. Thywissen (U. Toronto)

Ultracold atoms trapped in optical lattices provide an accurate implementation of the celebrated Hubbard model. This model describes an ensemble of particles trapped in a lattice. J. Thywissen's group in Toronto has recently implemented this model using ultracold Potassium atoms confined in optical lattice. By exciting the center of mass motion of the cloud they could measure the AC conductivity of the cloud that we compared to calculations based on a sem-classical theory. This comparison reveal the predominant role of the so-called umklapp processes corresponding to transitions between Brillouin zones.

Conductivity spectrum of ultracold atoms in an optical lattice, R. Anderson, F. Wang, P. Xu, V. Venu, S. Trotzky, F. Chevy, J.H. Thywissen, Physical Review Letters 122 (15), 153602 (2019)

## O. Goulko (UMass Boston) and C. Lobo (U. Southampton)

We study the applications of Boltzmann's equation to ultracold atom experiments. We have applied this type of approach to a broad array of experimental situations, from the spin-dynamics of Fermi gases, to the simulation of Weyl particles using ultracold atoms confined in quadrupolar magnetic potentials.

Quasithermalization of collisionless particles in quadrupole potentials, J. Lau, O. Goulko, T. Reimann, D. Suchet, C. Enesa, F. Chevy, C. Lobo, Physical Review A 101 (3), 033605 (2020)

Analog simulation of Weyl particles with ultracold atoms, D. Suchet et al. Europhys Lettes,

**114**26005 (2016)

## G. Orso (U. Paris Cité)

We explore many-body effective theories describing ultracold atomic gases in confined geometries. When the confinement is strong enough weakly correlated systems can be described by low-dimensionnal effective theories. However when interactions become to strong, virtual transitions towards excited states of the potential break the pure low dimensionality of the system, giving access to a novel family of systems mixing low-dimensionality and strong correlations.