Three-body bound states of two bosonic impurities immersed in a Fermi sea in 2D

Abstract

We consider two identical impurities immersed in a Fermi sea for a broad range of masses and for both interacting and non-interacting impurities. The interaction between the particles is described through attractive zero-range potentials and the problem is solved in momentum space. The two impurities can attach to a fermion from the sea and form three-body bound states. The energy of these states increase as function of the Fermi momentum k F , leading to three-body bound states below the Fermi energy. The fate of the states depends highly on two-and three-body thresholds and we find evidence of medium-induced Borromean-like states in 2D. The corrections due to particle-hole fluctuations in the Fermi sea are considered in the three-body calculations and we show that in spite of the fact that they strongly affect both the two-and three-body systems, the correction to the point at which the three-body states cease to exist is small.

Efimov physics in the presence of a Fermi sea

“…Depending on the statistics of majority particles, the system can be classified into Bose polarons and Fermi polarons, both having been realized in cold atoms experiments [23][24][25][26][27][28][29][30][31]. Theoretically, there have been a number of studies revealing the universal three-body correlations in Bose polaron and Fermi polaron systems [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. Nevertheless, the experimental detection of three-body correlation in polaron systems still remains at its infancy [47].…”

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

“…While the Fermi degeneracy can be achieved experimentally [44], the superfluid state has not yet been realized due to the strong three-body loss near the Feshbach resonance. 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].…”

Scattering of two heavy Fermi polarons: Resonances and quasibound states

“…When the impurity is tuned to strong attraction with the Fermi sea, it can form a bound state with one of the fermions. These, in turn, lead to an enhanced attraction between two impurities at short distance [4,5,28] and even to bipolaron bound states between two impurities in a Fermi sea [5,[29][30][31][32]. The Efimov bound states between two impurities and one fermion are characterized by discrete scaling relations [18,33].…”