Terahertz Radiations and Switching Phenomena of Intrinsic Josephson Junctions in High-Temperature Superconductors: Josephson Phase Dynamics in Long- and Short-Ranged Interactions

Abstract

Studies of intrinsic Josephson junctions (IJJs) of cuprate superconductors are reviewed. A system consisting of a few IJJs provides phenomena to test Josephson phase dynamics and its interaction between adjacent IJJs within a nm scale, which is peculiar to cuprate superconductors. Quasiparticle density of states, direct information of the Cooper-pair formation, is also revealed in the system. In contrast, the Josephson plasma radiation, electromagnetic wave radiation in sub-terahertz frequency range from an IJJ stack, is arisen by synchronous phase dynamics of hundreds IJJs coupling globally. This review summarizes a variety of physics found in IJJ systems with the capacitive and inductive couplings with different length scales of nm and 𝜇m, respectively.

Polarized terahertz electromagnetic-wave radiation from cuprate superconductor Bi2212 mesa structures

“…These include the d-wave nodal superconducting gap, the first-order vortex lattice melting transition, macroscopic quantum tunneling at low temperatures, and EM wave emissions resulting from the synchronous oscillations of numerous IJJs. 15) Terahertz EM wave emissions from IJJ stacks in Bi2212 single crystals were initially demonstrated in 2007 and were found to be the result of synchronized Josephson plasma waves excited in IJJs according to the ac Josephson effect. 9) We refer to such devices as Josephson plasma emitters (JPEs).…”