Magnetic field effects on THz radiation from Bi2Sr2CaCu2O8+δ mesa structures

In a previous our study, coherent and continuous electromagnetic radiation phenomena in mesa structures of Bi2Sr2CaCu2O8+δ single crystal have been investigated precisely in magnetic fields up to only 150 Oe. This experimental result showed that the emission intensity decreases sharply for the field parallel to the c-axis, while it decreases gradually as increasing magnetic field for the in-plane field. In order to improve the measurement, we developed a new system with a better angular resolution and much wider magnetic field range up to 6 T, and a mesa having much stronger THz emission power. The mesa structure is also changed to the stand-alone type of mesa, which produces higher power THz radiation with the ​ideal distribution of radiation. In this presentation, the recent detailed results will be shown in magnetic fields both parallel and perpendicular to the ab-plane of Bi2212, where the Josephson and pancake vortices are playing an important role for THz radiation. This work was supported in part by CREST-JST, WPI-MANA project (NIMS) and Strategic Initiative category (A) at the University of Tsukuba.