Polarization analysis of terahertz emission from Bi-2212 cross-whisker intrinsic Josephson junction and its refractive index

TL;DR

This study investigates the polarization and refractive index of terahertz emission from Bi-2212 whisker crystals, revealing a higher refractive index than bulk crystals and suggesting complex plasma excitation modes.

Contribution

It introduces a polarization measurement method to analyze THz emission modes and estimates the refractive index of whisker crystals, supported by simulation validation.

Findings

Refractive index of whisker crystals is higher than bulk crystals.

Polarization analysis effectively estimates THz emission modes.

Simulation indicates complex plasma excitation modes.

Abstract

Polarization analyses of the terahertz (THz) emission from Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ whisker crystals used for superconducting THz emitters were conducted. The THz emission mode was estimated by a simple polarization measurement, and a simulation study was conducted to examine the validity of the polarization analysis. The refractive index of whisker crystals revealed through the polarization analyses was greater than that of bulk single crystals and agreed well with our previous THz emission report. The simulation study suggested the complex plasma excitation mode of the THz emission, and an interpretation of the refractive index obtained in this study is provided.