Collective responses of Bi-2212 stacked junction to 100 GHz microwave radiation under magnetic field oriented along the c-axis

TL;DR

This study investigates how Bi-2212 stacked Josephson junctions respond to 100 GHz microwave radiation under an applied magnetic field, revealing collective synchronization and harmonic generation up to the 10th order.

Contribution

It demonstrates the magnetic field enabled collective Shapiro steps in all 50 intrinsic Josephson junctions and observes high harmonic generation and flux-flow steps influenced by microwave power.

Findings

Collective Shapiro steps observed at 0.1 T magnetic field.

Up to 10 harmonics of the fundamental Shapiro step detected.

Microwave induced flux-flow step frequency exceeds 1 THz at high power.

Abstract

We studied a response of Bi-2212 mesa type structures to 100 GHz microwave radiation. We found that applying magnetic field of about 0.1 T across the layers enables to observe collective Shapiro step response corresponding to a synchronization of all 50 intrinsic Josephson junctions (IJJ) of the mesa. At high microwave power we observed up to 10th harmonics of the fundamental Shapiro step. Besides, we found microwave induced flux-flow step position of which is proportional to the square root of microwave power and that can exceed at high enough powers 1 THz operating frequency of IJJ oscillations.