Abstract
Charge density wave (CDW) is one of the most fundamental quantum phenomena in solids. Different from ordinary metals in which only single-particle excitations exist, CDW also has collective excitations and can carry electric current in a collective fashion. Manipulating this collective condensation for applications has long been a goal in the condensed matter and materials community. We show that the CDW system of 1T-TaS(2) is highly sensitive to light directly from visible down to terahertz, with current responsivities on the order of ~1 AW(-1) at room temperature. Our findings open a new avenue for realizing uncooled, ultrabroadband, and sensitive photoelectronics continuously down to the terahertz spectral range.