On Chip Photothermoelectric Logic Gates with Sub‐Picosecond Photothermal Response

Abstract On‐chip electronic devices driven by ultrafast light represent a promising approach to surpass traditional information processing speeds. However, practical implementation has been limited by the requirement for material with complex heterostructure and femtosecond lasers with high pulse energy, carrier‐envelope phase stability, and few‐cycle durations. To address this limitation, an on‐chip logic gate is developed on a metallic material platform based on the photothermoelectric effect (PTE) and plasma resonance absorption of gold. By manipulating the light polarization, hot carrier migration is controlled, achieving a high polarization ratio and bipolar response. Meanwhile, time‐resolved transient absorption spectroscopy demonstrates that the switching time is on the sub‐picosecond scale. The logic gate used two picojoule‐level laser pulses as inputs, outputting nanoampere‐level currents with controllable polarity. This design provides a convenient fabrication process, promising for large‐scale high speed logic computing devices.