Terahertz sensing based on the nonlinear electrodynamics of the two-dimensional correlated topological semimetal TaIrTe4

The development of terahertz (THz) sensing technologies is limited by the lack of sensitive, broadband, and fast terahertz detectors. Thermal bolometers are bulky and slow, whereas electronic terahertz detectors (such as Schottky diodes) are fast, but their sensitivity degrades quickly outside a narrow frequency window. Here, we show that a two-dimensional correlated topological semimetal, tantalum iridium telluride (TaIrTe4), has a large room temperature nonlinear Hall effect, and that the interaction between this effect and terahertz nonlinear electrodynamics can be used as a mechanism for terahertz sensing. Our photodetectors exhibit a high sensitivity (noise equivalent power of around 1 pW Hz-1/2) and a large zero-bias responsivity (around 0.3 A W-1) a broadband spectral range (0.1–10 THz) at room temperature with intrinsic ultrafast response time (around ps). The zero-bias responsivity and noise equivalent power performance can be further improved (to 18 A W-1 and 0.05 pW Hz-1/2, respectively) by introducing gate-tunable electron correlations.