Generation of very low temperatures has been crucially important for applications and fundamental research, as low-temperature quantum coherence enables operation of quantum computers and formation of exotic quantum states, such as superfluidity and superconductivity. One of the major techniques to reach milli-Kelvin temperatures is adiabatic demagnetization refrigeration. This method uses almost non-interacting magnetic moments of paramagnetic salts where large distances suppress interactions between the moments. The large spatial separations are facilitated by water molecules, with a drawback of reduced stability of the material. Here, we show that the water-free frustrated magnet KBaYb(BO₃)₂ can be ideal for refrigeration, achieving at least 22 mK. Compared to conventional refrigerants, KBaYb\({({{\rm{BO}}}_{3})}_{2}\) does not degrade even under high temperatures and ultra-high vacuum. Further, its magnetic frustration and structural randomness enable cooling to temperatures several times lower than the energy scale of magnetic interactions, which is the main limiting factor for the base temperature of conventional refrigerants.

低温的产生对于应用和基础研究至关重要，因为低温量子相干能够使量子计算机运行并形成奇特的量子态，例如超流态和超导性。达到毫开尔文温度的主要技术之一是绝热去磁制冷。该方法使用顺磁性盐几乎不相互作用的磁矩，其中较大的距离抑制了磁矩之间的相互作用。水分子促进了较大的空间分隔，但缺点是材料的稳定性降低。在这里，我们显示了无水沮丧的磁体KBaYb（BO ₃）₂可以理想地用于制冷，至少达到22 mK。与常规制冷剂相比，KBaYb \（{{{{rm {BO}}} _ {3}} _ {2} \即使在高温和超高真空下也不会降解。此外，其磁阻和结构随机性使冷却到比磁相互作用能级低几倍的温度，这是常规制冷剂基本温度的主要限制因素。