Quasiparticle poisoning effects on the dynamics of topological Josephson junctions

authored by: Daniel Frombach, Patrik Recher
Abstract: The fractional Josephson effect remains one of the decisive hallmarks of topologically protected Majorana zero modes. We analyze the effects of parity violating quasiparticle poisoning onto the current voltage characteristics of topological Josephson junctions. We include poisoning events directly within the resistively shunted junction (RSJ) model in the overdamped limit both in the short- A nd long-junction regime. We calculate the current voltage characteristics numerically where poisoning is modeled either via additional rates in the Fokker-Planck equations or by a time dependent parity and compare them to the limits of no and strong poisoning rates which we obtain analytically. Combining the tilted washboard potential with poisoning events, we show that the critical current of the long junction limit can be used as a probe of the junction topology even in the high temperature poisoning case where relaxation and excitation processes are equally likely. Using the tilted washboard potential model we develop three different schemes to measure the poisoning rate thereby also extending the consideration to two pairs of helical edge states containing a constriction that allows for tunneling between the two pairs of edge states.
External Organisation(s): Technische Universität Braunschweig
Type: Article
Journal: Physical Review B
Volume: 101
ISSN: 2469-9950
Publication date: 17.03.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Electronic version(s): https://doi.org/10.1103/PhysRevB.101.115304 (Access: Unknown)

BibTeX

@article{554ba10afd504c2aa00242d1fe7ac576,
title = "Quasiparticle poisoning effects on the dynamics of topological Josephson junctions",
abstract = "The fractional Josephson effect remains one of the decisive hallmarks of topologically protected Majorana zero modes. We analyze the effects of parity violating quasiparticle poisoning onto the current voltage characteristics of topological Josephson junctions. We include poisoning events directly within the resistively shunted junction (RSJ) model in the overdamped limit both in the short- A nd long-junction regime. We calculate the current voltage characteristics numerically where poisoning is modeled either via additional rates in the Fokker-Planck equations or by a time dependent parity and compare them to the limits of no and strong poisoning rates which we obtain analytically. Combining the tilted washboard potential with poisoning events, we show that the critical current of the long junction limit can be used as a probe of the junction topology even in the high temperature poisoning case where relaxation and excitation processes are equally likely. Using the tilted washboard potential model we develop three different schemes to measure the poisoning rate thereby also extending the consideration to two pairs of helical edge states containing a constriction that allows for tunneling between the two pairs of edge states.",
author = "Daniel Frombach and Patrik Recher",
note = "Funding information: We thank Fernando Dom{\'i}nguez for very useful feedback on the paper, and Wolfgang Belzig and Markus Etzkorn for enlightening discussions. We acknowledge financial support from the Lower Saxony Ph.D.-programme “Contacts in Nanosystems”, the Braunschweig International Graduate School of Metrology B-IGSM, and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via Germany's Excellence Strategy EXC-2123 QuantumFrontiers 390837967 and the Research Training Group GrK1952/1 “Metrology for Complex Nanosystems.",
year = "2020",
month = mar,
day = "17",
doi = "10.1103/PhysRevB.101.115304",
language = "English",
volume = "101",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Institute of Physics",
number = "11",
}