Penna Vittorio, Richaud Andrea
Department of Applied Science and Technology and u.d.r. CNISM, Politecnico di Torino, I-10129, Torino, Italy.
Sci Rep. 2018 Jul 6;8(1):10242. doi: 10.1038/s41598-018-28573-w.
We show that, depending on the ratio between the inter- and the intra-species interactions, a binary mixture trapped in a three-well potential with periodic boundary conditions exhibits three macroscopic ground-state configurations which differ in the degree of mixing. Accordingly, the corresponding quantum states feature either delocalization or a Schrödinger cat-like structure. The two-step phase separation occurring in the system, which is smoothed by the activation of tunnelling processes, is confirmed by the analysis of the energy spectrum that collapses and rearranges at the two critical points. In such points, we show that also Entanglement Entropy, a quantity borrowed from quantum-information theory, features singularities, thus demonstrating its ability to witness the double mixining-demixing phase transition. The developed analysis, which is of interest to both the experimental and theoretical communities, opens the door to the study of the demixing mechanism in complex lattice geometries.
我们表明，根据种间和种内相互作用之间的比率，被困在具有周期性边界条件的三阱势中的二元混合物呈现出三种宏观基态构型，它们在混合程度上有所不同。相应地，对应的量子态具有离域或薛定谔猫状结构。通过对在两个临界点坍塌和重新排列的能谱分析，证实了系统中发生的两步相分离，这种相分离通过隧穿过程的激活而变得平滑。在这些点上，我们表明，从量子信息理论借用的量——纠缠熵也具有奇异性，从而证明了它见证双混合 - 去混合相变的能力。所开展的分析对实验和理论界都具有重要意义，为研究复杂晶格几何结构中的去混合机制打开了大门。
