SAIP2014

Can Shapiro step subharmonics be "charged"?

10 Jul 2014, 14:40

20m

D Les 201

Oral Presentation Track A - Division for Physics of Condensed Matter and Materials DPCMM1

Speaker

Dr Hermann Azemtsa Donfack (University of South Africa)

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

The system of superconducting layers found in high temperature superconductors (HTSC) such as Bi₂Sr₂CaCu₂O_{8+&delta} (Bi-2122) represent intrinsic Josephson junctions (IJJs). The locking of the Josephson oscillations (&omega_J) of each junction of the IJJ to the frequency (&omega_ext) of external electromagnetic radiation leads to the appearance at quantized voltages of the so-called Shapiro steps in the current voltage characteristics (IV-characteristics). Many devices in existence exploit this effect, notably voltage standards. Therefore, a detailed study of the Shapiro steps and their subharmonics in the intrinsic Josephson junctions at different resonance conditions presents important research questions with potential for different applications.

Using the capacitively coupled Josephson junction with diffusion current (CCJJ + DC model), we performed precise numerical study of phase dynamics of intrinsic Josephson junctions under external electromagnetic radiation. We survey the different Shapiro steps (SS) subharmonics found in these systems. We establish a link between the "charging" of superconducting layers in bias-current interval corresponding to SS subharmonics, and the existence of longitudinal plasma waves (LPW)
in the system.

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

No

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

N/A

Peer reviewing

Paper

Accepted on 17 Mar 2015 by Steven Karataglidis

166ab_2corrections.pdf