Wayne Jordan Chetcuti, Andreas Osterloh, Luigi Amico, Juan Polo
SciPost Phys. 15, 181 (2023) ·
published 30 October 2023

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Interacting Ncomponent fermions spatially confined in ringshaped potentials display specific coherence properties. The orbital angular momentum per particle of such systems can be quantized to fractional values specifically depending on the particleparticle interaction. Here we demonstrate how to monitor the state of the system through homodyne (momentum distribution) and selfheterodyne system's expansion. For homodyne protocols, the momentum distribution is affected by the particle statistics in two distinctive ways. The first effect is a purely statistical one: at zero interactions, the characteristic hole in the momentum distribution around the momentum k=0 opens up once half of the SU(N) Fermi sphere is displaced. The second effect originates from the interaction: The fractionalization in the interacting system manifests itself by an additional "delay" in the flux for the occurrence of the hole, that now becomes a characteristic minimum at k=0. We demonstrate that the angular momentum fractional quantization is reflected in the selfheterodyne interference as specific dislocations in interferograms. Our analysis demonstrates how the study of the interference fringes grants us access to both number of particles and number of components of SU(N) fermions.
Andreas Osterloh, Juan Polo, Wayne J. Chetcuti, Luigi Amico
SciPost Phys. 15, 006 (2023) ·
published 11 July 2023

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We consider a gas of repulsive $N$component fermions confined in a ringshaped potential, subjected to an effective magnetic field. For large repulsion strengths, we work out a Bethe ansatz scheme to compute the twopoint correlation matrix and then the oneparticle density matrix. Our results hold in the mesoscopic regime of finite but sufficiently large number of particles and system size that are not accessible by numerics. We access the momentum distribution of the system and analyse its specific dependence of interaction, magnetic field and number of components $N$. In the context of cold atoms, the exact computation of the correlation matrix to determine the interference patterns that are produced by releasing cold atoms from ring traps is carried out.
Wayne J. Chetcuti, Tobias Haug, LeongChuan Kwek, Luigi Amico
SciPost Phys. 12, 033 (2022) ·
published 21 January 2022

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We study the persistent current in a system of SU($N$) fermions with repulsive interaction confined in a ringshaped potential and pierced by an effective magnetic flux. By applying a combination of Bethe ansatz and numerical analysis, we demonstrate that, as a combined effect of spin correlations, interactions and applied flux a specific phenomenon can occur in the system: spinon creation in the ground state. As a consequence, peculiar features in the persistent current arise. The elementary flux quantum, which fixes the persistent current periodicity, is observed to evolve from a single particle one to an extreme case of fractional flux quantum, in which one quantum is shared by all the particles. We show that the persistent current depends on the number of spin components $N$, number of particles and interaction in a specific way that in certain physical regimes has universality traits. At integer filling fractions, the persistent current is suppressed above a threshold of the repulsive interaction by the Mott spectral gap. Despite its mesoscopic nature, the current displays a clear finite size scaling behavior. Specific parity effects in the persistent current landscape hold.
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in Submissions  report on Interference dynamics of matterwaves of SU($N$) fermions