Impact of Antenna Metal’s Thicknesses and Structures on Terahertz (THz) Wave Generation Performance of Spintronic Emitters

We compare THz wave generation performances of diabolo-shaped spintronic antennas with 3 nm, 100 nm and 200 nm Pt thicknesses at the antenna flares. The center of these antennas where spin-to-charge current conversion occurs is composed of 2 nm Fe and 3 nm Pt metal layer. THz- time domain spectroscopy (THz – TDS) showed the most efficient emission, especially at frequencies <1.5 THz, from the diabolo antenna with 200 nm Pt layer. We also compare THz emission amplitude of diabolo and rectangular spintronic antennas composed of2 nm Fe and 3 nm Pt layer at the center and 2 nm Fe and 200 nm Pt layer at the displacement current direction. Time-domain and frequency-domain waveforms showed higher emission amplitude from the rectangular antenna especially at frequencies >1.1 THz.