Quantum chromodynamics (QCD)-like phase diagram with Efimov trimers and Cooper pairs in resonantly interacting SU(3) Fermi gases

Abstract

We investigate color superfluidity and trimer formation in resonantly interacting SU(3) Fermi gases with a finite interaction range. The finite range is crucial to avoid the Thomas collapse and treat the Efimov effect occurring in this system. Using the Skorniakov-Ter-Martirosian equation with medium effects, we show the effects of the atomic Fermi distribution on the Efimov trimer energy at finite temperature. We show the critical temperature of color superfluidity within the many-body T-matrix approximation. In this way, we can provide a first insight into the phase diagram as a function of the temperature T and the chemical potential μ. This phase diagram consists of trimer, normal, and colorsuperfluid phases, and is similar to that of quantum chromodynamics at finite density and temperature.

Three-body crossover from a Cooper triple to bound trimer state in three-component Fermi gases near a triatomic resonance

“…We propose the ground-state phase diagram in the space of the scattering length and the range parameter. It is in contrast to the previous works in which the phase diagram is shown in terms of the negative effective range associated with the Feshbach coupling in the twochannel model [55,58]. Moreover, we give a physical interpretation of the shift of three-body loss due to the Fermi surface effect as an emergence of Cooper triples.…”

“…While it is similar to the phase diagram for the Lifshitz transition at a = a − from the trimer Fermi liquid to the superfluid state at negative scattering lengths within the mean-field and in-vacuum three-body analyses [55], our results imply that competing fluctuations associated with the pair-to-triple transition give a rich physics on this system. Such a possibility has also been predicted in a diagrammatic approach at finite temperature [58]. Also, the crossover from the Cooper triple to the tightly-bound trimer state is analogous to the BCS-BEC crossover near the Feshbach resonance where Cooper pairs continuously change to tightly-bound molecules.…”

“…In this regard, numerous attention is paid to understand how the Efimov trimer behaves in the presence of Fermi seas [45][46][47][48][49][50][51][52][53]. Moreover, a unique crossover phenomenon involving superfluidity and trimer gases has been investigated [54][55][56][57][58].…”

Condensation of Cooper Triples

“…In a three-component fermionic system, the formation of Cooper triples, which correspond to a three-body version of Cooper pairs, has been studied in the presence of two-body and three-body interactions [7,8]. It is also under investigation how medium corrections affect properties of Efimov trimers [9][10][11][12][13][14][15][16]. In addition, an inmedium cluster state consisting of more than three particles such as a Cooper quartet has also been pointed out [17,18].…”

“…Before calculating the order parameter, we consider the non-interacting case by setting ∆ k → 0. In such a case, we obtain 11) and (12), where θ(x) is the step function. This result indicates that Eq.…”