  Recently, thermal switching has been extensively studied because it is a key
component for thermal management in electronic devices. Here, we show a huge
magneto-thermal-switching ratio (MTSR) in pure Nb at temperatures lower than
its superconducting transition temperature (Tc = 9.2 K). The MTSR increases
with decreasing temperature, and MTSR of 650% was observed at T = 2.5 K under H
= 4.0 kOe. The thermal switching in superconductors with the huge MTSR will be
useful for improvement of the performance of low-temperature electronic
devices.
