Ultrafast THz Studies in Spintronic Devices

Student’s name: Jacob Clerc Home Institution: Presbyterian College NNCI Site: RTNN @ NC State University REU Principal Investigator: Dr. Kenan Gundogdu, Department of Physics, NC State University REU Mentor: Malek Abdelsamei, Department of Physics, NC State University Abstract: Terahertz (THz) radiation is located between visible light and radio waves on the IR spectrum. Because these frequencies are hard to access by both electronic oscillators and optical transitions, this region is also known as the "THz gap”. As the demand to achieve large bandwidths in wireless communications increases, developing THz sources has become a hot research topic. One emerging technique for generating and detecting THz is based on ultrafast lasers. In this project, we employ this technique to explore the use of spintronic THz generation. In spintronic THz emission, we optically excite a hetero-structural material (ex: NiFe/Pt) with a femtosecond ultrashort pulse to generate a THz field utilizing the inverse spin Hall effect in the presence of an externally applied magnetic field. We use this method as a means to create and manipulate THz fields. One approach we use in manipulating these fields is to process the multilayered structure in the form of photonic resonators, enabling the amplification of certain THz fields and filtering others. Moreover, we investigate the potential of using chiral effects in spintronic THz generation. The obtained data aids in understanding the characteristics of THz signals emitted by spintronic processes, which can be eventually exploited in the emerging application of 5G and 6G communications.