Geometrical Resonance Conditions for THz Radiation from the Intrinsic Josephson Junctions in Bi2Sr2CaCu2O8+d

TL;DR

This study investigates subterahertz radiation from intrinsic Josephson junction mesas in Bi2Sr2CaCu2O8+d, revealing that the emission frequency aligns with both the ac Josephson effect and cavity resonance modes, with higher harmonics indicating a dual-source mechanism.

Contribution

It demonstrates the combined role of ac Josephson effect and cavity resonance in THz emission from intrinsic Josephson junctions, supported by experimental observations.

Findings

Radiation frequency matches ac Josephson and cavity resonance conditions.

Higher harmonics confirm the dual-source radiation mechanism.

Emission observed across various mesa shapes and sizes.

Abstract

Subterahertz radiation emitted from a variety of short rectangular-, square-, and disk-shaped mesas of intrinsic Josephson junctions fabricated from a Bi2Sr2CaCu2O8+d single crystal was studied from the observed I-V characteristics, far-infrared spectra, and spatial radiation patterns. In all cases, the radiation frequency satisfies the conditions both for the ac Josephson effect and for a mesa cavity resonance mode. The integer higher harmonics observed in all spectra imply that the ac Josephson effect plays the dominant role in the novel dual-source radiation mechanism.