Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

THz waves are electromagnetic waves with frequencies ranging from 0.1 to 10 THz (30 to 3000 μm in wavelength), which have both the transparency of radio waves and the straightness of light waves. They are expected to be applied in nondestructive testing (infrastructure defect inspection, etc.), disease diagnosis (diabetes, etc.), and ultrahigh-speed wireless communications (6G). On the other hand, layered materials such as MoS2 and graphene can be used to fabricate devices by mechanical exfoliation and stacking, and offer significant advantages such as ultra-high speed and ultra-low power consumption. Using these two-dimensional materials, it is expected to create terahertz light sources and detectors that are smaller, more powerful, more efficient, and more sensitive than conventional solid-state electronic devices and nonlinear optical materials made from Si and compound semiconductors.

My research aims to create a new concept device by introducing plasmonic effects in heterostructures of two-dimensional materials, and to demonstrate its feasibility as a THz light source and detector. Different from the present THz devices based on the instability in momentum space like PIN diode and Gunn diode, our device will realize the THz emission and detection implemented with the real space carrier instability, which will benefit not only the solid-state physics of 2D materials, but also the THz technologies and related applications.