Probe for bound states of SU(3) fermions and colour deconfinement

Abstract

Fermionic artificial matter realized with cold atoms grants access to an unprecedented degree of control on sophisticated many-body effects with an enhanced flexibility of the operating conditions. Here, we consider three-component fermions with attractive interactions to study the formation of complex bound states, whose nature goes beyond the standard fermion pairing occurring in quantum materials. Such systems display clear analogies with quark matter. We address the nature of the bound states of a three-component fermionic system in a ring-shaped trap through the persistent current. In this way, we demonstrate that we can distinguish between color superfluid and trionic bound states. By analyzing finite temperature effects, we show how finite temperature can lead to the deconfinement of bound states. For weak interactions, the deconfinement occurs because of scattering states. In this regime, the deconfinement depends on the trade-off between interactions and thermal fluctuations. For strong interactions the features of the persistent current result from the properties of a suitable gas of bound states.

Interference dynamics of matter-waves of SU($N$) fermions

“…As such, the ratio between the hopping and interaction parameters dictates the physics that we observe in our system. For strong attractive interactions (|U| ≫ t), SU(N ) fermions are able to form bound states of different types and nature, which in turn causes part of the particles to localize together, while still adhering to the Pauli exclusion principle [44,[57][58][59]. On the other hand, strong repulsive interactions (U ≫ t) causes the fermions to be restricted in place in different lattice sites.…”

“…Persistent currents in two-component ultracold fermions have been experimentally studied very recently [41,42]. For N -component fermions confined in ring potentials, the theory predicts a fractional quantization of the orbital angular momentum per particle (henceforth referred to as angular momentum), with important differences arising on whether the atoms are subject to repulsive or attractive interaction [43,44]. Such specific properties of quantization are expected to provide the core to fabricate quantum devices with enhanced sensitivity [23].…”

Exact one-particle density matrix for SU(N) fermionic matter-waves in the strong repulsive limit

“…This state takes the role of the non-degenerate triplet state of SU(2) in the zero field groundstate for an even species number occupation. b) Non-zero flux-The analysis of non-zero magnetic flux is motivated from an atomtronics context [28,37]. As mentioned previously, for strong repulsive interactions a fractionalization of the persistent currents in the model is observed [41,42].…”

“…Recently, the relevance of N-component fermions has been significantly boosted through the experimental realizations of alkaline earth-like fermionic atomic gases [16][17][18][19]; in there, the two-body interactions resulted to be SU(N )-symmetric, reflecting the absence of hyperfine coupling between the atoms' electronic and nuclear degrees of freedom [20][21][22]. Such artificial matter is relevant for high precision measurements [23,24] and has the potential of considerably expanding the scope of cold atoms quantum simulators [16,[25][26][27][28]. Here, we focus on SU(N ) fermions described by a Hubbard type model [20,22].…”

“…The one-body density matrix plays a crucial role in different schemes of time-of-flight expansions in cold atoms settings [28,[34][35][36][37][38]. The effect of an artificial magnetic field in neutral two-component fermions confined in tight toroidal-shaped potentials was explored in recent experiments [39,40].…”