Designing coupled metal slot antennas for detecting micron-sized 2D material in terahertz regime

The metallic meta-surface which enables measurements of micron-sized two-dimensional (2D) materials with millimeter-wavelength terahertz wave is introduced to overcome diffraction limit. We induce strong light (terahertz wave)-matter (15-$\mu$ m-sized graphite) interaction by using a slot antenna making electric-field confinement and enhancement of electromagnetic waves. When micron-sized graphite partially covers the slot antenna, the resonance transmissions are significantly reduced. This result implies that strong coupling between terahertz wave and metallic graphite is accomplished through the slot antennas, which can be expanded toward various 2D materials in the regime of millimeter-wavelength.