# Archive ouverte HAL – Dimer-dimer zero crossing and dilute dimerized liquid in a one-dimensional mixture

### A. Pricoupenko 1, 2 D. S. Petrov 1

#### Physical Review A, American Physical Society, 2018, 97 (6), 〈10.1103/PhysRevA.97.063616〉

We consider the system of dimers formed in a one-dimensional mass-balanced Bose-Bose mixture of species $\sigma=\uparrow$, $\downarrow$ with attractive interspecies and repulsive intraspecies contact interactions. In the plane parametrized by the ratios of the coupling constants $g_{\uparrow\uparrow}/|g_{\uparrow\downarrow}|$ and $g_{\downarrow\downarrow}/|g_{\uparrow\downarrow}|$ we trace out the curve where the dimer-dimer interaction switches from attractive to repulsive. We find this curve to be significantly (by more than a factor of 2) shifted towards larger $g_{\sigma\sigma}$ (or smaller $|g_{\uparrow\downarrow}|$) compared to the mean-field stability boundary $g_{\uparrow\uparrow}g_{\downarrow\downarrow}=g_{\uparrow\downarrow}^2$. For a weak dimer-dimer attraction we predict a dilute dimerized liquid phase stabilized against collapse by a repulsive three-dimer force.

• 1. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
• 2. ENS Lyon - École normale supérieure - Lyon