Applying a magnetic field to a solid changes its thermal-transport properties. Although such magneto-thermal-transport phenomena are usually small effects, giant magneto-thermal resistance has recently been observed in spintronic materials and superconductors, opening up new possibilities in thermal management technologies. However, the thermal conductivity conventionally changes only when a magnetic field is applied due to the absence of nonvolatility, which limits potential applications of thermal switching devices. Here, we report the observation of nonvolatile thermal switching that changes the electron thermal conductivity when a magnetic field is applied and retains the value even when the field is turned off. This unconventional magneto-thermal switching arises in commercial Sn-Pb solders and is realized by phase-separated superconducting states and resultant nonuniform magnetic flux distributions. This result confirms the versatility of the observed phenomenon and aids the development of active solid-state thermal management devices.

对固体施加磁场会改变其热传输特性。尽管这种磁热传输现象通常影响很小，但最近在自旋电子材料和超导体中观察到了巨大的磁热阻，为热管理技术开辟了新的可能性。然而，由于缺乏非易失性，传统上热导率只有在施加磁场时才会改变，这限制了热开关器件的潜在应用。在这里，我们报告了非易失性热开关的观察结果，该热开关在施加磁场时改变电子热导率，并且即使在磁场关闭时也保留该值。这种非常规的磁热切换出现在商业 Sn-Pb 焊料中，并通过相分离的超导状态和由此产生的不均匀磁通量分布来实现。这一结果证实了所观察到的现象的多功能性，并有助于主动固态热管理器件的开发。