A quantum liquid in a heterogeneous mixture of ${}^{41}\mathrm{K}$ and ${}^{87}\mathrm{Rb}$ atoms is studied using the diffusion Monte Carlo method and density-functional theory. The perturbative Lee-Huang-Yang term for a heterogeneous mixture is verified and it is proved to be valid only near the gas-liquid transition. Based on the equations of state of the bulk mixture, calculated with diffusion Monte Carlo, extensions to Lee-Huang-Yang corrected mean-field energy functionals are presented. Using density-functional theory, a systematic comparison between different functionals is performed, focusing on the critical atom number, surface tension, surface width, Tolman length, and compressibility. These results are given as a function of the interspecies interaction strength, within the stability domain of the liquid mixture.

中文翻译：

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在 K-Rb Bose 混合物中稀释量子液体

非均质混合物中的量子液体 ${}^{41}\mathrm{钾}$ 和 ${}^{87}铷$使用扩散蒙特卡罗方法和密度泛函理论研究原子。验证了非均质混合物的微扰 Lee-Huang-Yang 项，并证明它仅在气-液转变附近有效。基于散装混合物的状态方程，用扩散蒙特卡罗计算，提出了对 Lee-Huang-Yang 校正平均场能量函数的扩展。使用密度泛函理论，对不同泛函进行了系统比较，重点关注临界原子数、表面张力、表面宽度、托尔曼长度和可压缩性。在液体混合物的稳定域内，这些结果是作为种间相互作用强度的函数给出的。