Abstract
Sensitive photodetectors showing large quantum efficiencies and broad dynamic ranges are essential components for on-chip integrated photonic quantum platforms and for probing quantum correlations in metrological sources. However, at terahertz (THz) frequencies, this is a very challenging task owing to the lack of high-absorption materials and thermal effects that impact their noise figure. Here, we develop antenna-coupled tunnel field-effect transistors, based on multilayer graphene/hBN/bilayer graphene/hBN that detect multiwavelength beams at frequencies ∼3 THz with record performances. We reach noise-equivalent powers of ∼10(-12) WHz(-1/2), a power dynamic range exceeding 5 orders of magnitude, limited by the maximum output power (0.8 mW) of the employed source, and a minimum detectable power at the nW-level, in a frequency-scalable device architecture. Our results open intriguing perspectives for the statistical analysis of quantum intensity correlations in nonclassical light sources operating in the underexploited THz frequency gap, between technologically mature domains (microwave, visible, near-infrared) that currently dominate the field of quantum technologies.