A wide-range topological thermometer with Ta2Pd3Te5: From power-law response to application prospects

In recent decades, there has been a persistent pursuit of applications for surface/edge states in topological systems, driven by their dissipationless transport effects. This work demonstrates the remarkable properties of the topological material Ta2Pd3Te5, as a thermometer. At low temperatures, it shows a power-law correlation in temperature-dependent resistance, while behaving like a semiconductor at high temperatures. This dual behavior effectively mitigates the issue of infinite resistance in semiconductor thermometers at ultra-low temperatures, making it ideal for millikelvin-range refrigerators. Through chemical doping, thickness adjustment, and gate voltage control, its performance can be finely tuned, and can also enable micron-scale local temperature measurement from millikelvin to room temperature. Furthermore, this thermometer exhibits excellent temperature sensitivity and resolution, and can be fine-tuned to show small magnetoresistance. In summary, the Ta2Pd3Te5 thermometer, also referred to as a topological thermometer, exhibits significant potential for measuring a wider range of temperatures compared to conventional low-temperature thermometers.