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arXiv · 2011.04023

Magnetic Phase Transition in the Ground-State Phase Diagram of Binary Bose Gases in Optical Lattices

Laurent de Forges de Parny·Valéry Rousseau
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Abstract

We investigate the ground-state phase diagram of interacting binary Bose gases trapped in two-dimensional optical lattices by means of quantum Monte Carlo simulations. Our simulations reveal a magnetic phase transition from a $x-y$ ferromagnetic-order to a spin insulator inside the Mott insulating phase with two particles per site for quasi-balanced on-site inter- and intra-particle interactions, i.e., $U_{\uparrow \downarrow} \lesssim U$. This 3D-XY transition is characterized by the establishment of a finite local magnetic moment along the $z$-axis, ferromagnetic correlations in the $x-y$ plan and by counterflow superfluidity inside the Mott phase. When decreasing $U_{\uparrow \downarrow}/U$, this transition merges with the Mott-superfluid transition and becomes first-order. The merging of the two transitions is investigated with respect to $U_{\uparrow \downarrow}/U$ parameter.

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Laurent de Forges de Parny, Valéry Rousseau. 2020-11-08. Magnetic Phase Transition in the Ground-State Phase Diagram of Binary Bose Gases in Optical Lattices. https://doi.org/10.1209/0295-5075/134/16001

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