scholarly journals A Novel Treatment of the Josephson Effect

2021 ◽  
Author(s):  
Jacob Szeftel ◽  
Nicolas Sandeau ◽  
Michel Abou Ganthous
Keyword(s):  
Radio Frequency ◽  
Josephson Junction ◽  
Thermal Equilibrium ◽  
Josephson Effect ◽  
Negative Resistance ◽  
Persistent Currents ◽  
Novel Treatment ◽  
Rf Signal ◽  
Bound Electrons

A new picture of the Josephson effect is devised. The radio-frequency (RF) signal, observed in a Josephson junction, is shown to stem from bound electrons, tunneling periodically through the insulating film. This holds also for the microwave mediated tunneling. The Josephson effect is found to be conditioned by the same prerequisite worked out previously for persistent currents, thermal equilibrium and occurence of superconductivity. The observed negative resistance behaviour is shown to originate from the interplay between the normal and superconducting currents.

Open Localization in Micro LeadFrame Package Using Space Domain Reflectometry

2013 ◽  
Author(s):  
J. Gaudestad ◽  
V. Talanov ◽  
A. Orozco ◽  
M. Marchetti
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Standing Wave ◽  
High Resistance ◽  
Space Domain ◽  
The Past ◽  
Open Defects ◽  
Rf Electronics ◽  
Rf Signal ◽  
The Magnetic Field

Abstract In the past couple years, Space Domain Reflectometry (SDR) has become a mainstream method to locate open defects among the major semiconductor manufacturers. SDR injects a radio frequency (RF) signal into the open trace creating a standing wave with a node at the open location. The magnetic field generated by the standing wave is imaged with a SQUID sensor using RF electronics. In this paper, we show that SDR can be used to non-destructively locate high resistance failures in Micro LeadFrame Packages (MLP).

scholarly journals Revealing the interference effect of Majorana fermions in a topological Josephson junction

2018 ◽  
Vol 9 ◽  
pp. 520-529 ◽  
Author(s):  
Jie Liu ◽  
Tiantian Yu ◽  
Juntao Song
Keyword(s):  
Josephson Junction ◽  
Interference Effect ◽  
Josephson Effect ◽  
Andreev Reflection ◽  
Local Density ◽  
Localized States ◽  
Majorana Fermions ◽  
Local Density Of States ◽  
Single Side ◽  
Period Oscillation

We study theoretically the local density of states (DOS) in a topological Josephson junction. We show that the well-known 4π Josephson effect originates from the interference effect between two Majorana fermions (MFs) that are localized at the Josephson junction. In addition, the DOS for electrons (holes) shows the 4π interference information along each parity conserved energy spectrum. The DOS displays a 2π period oscillation when two trivial states interfere with each other. This means that the DOS information may be used to distinguish the MFs from trivial localized states. We suggest that the interference effect and the DOS can be detected by using two STM leads or two normal leads. A single side lead can only detect the Andreev reflection tunneling process in the junction, which cannot reveal information about the interference effect in general. However, using two side leads, we can reveal information about the interference effect of the MFs as well as the DOS by combining Andreev reflection with the electron transmission process.

scholarly journals Induced Topological Superconductivity in a BiSbTeSe2-Based Josephson Junction

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 794 ◽  
Author(s):  
Bob de Ronde ◽  
Chuan Li ◽  
Yingkai Huang ◽  
Alexander Brinkman
Keyword(s):  
Radio Frequency ◽  
Josephson Junction ◽  
Frequency Response ◽  
Systematic Study ◽  
Bound States ◽  
Shapiro Step ◽  
Majorana Bound States ◽  
Irradiation Power ◽  
Radio Frequency Waves ◽  
High Irradiation

A 4 π -periodic supercurrent through a Josephson junction can be a consequence of the presence of Majorana bound states. A systematic study of the radio frequency response for several temperatures and frequencies yields a concrete protocol for examining the 4 π -periodic contribution to the supercurrent. This work also reports the observation of a 4 π -periodic contribution to the supercurrent in BiSbTeSe 2 -based Josephson junctions. As a response to irradiation by radio frequency waves, the junctions showed an absence of the first Shapiro step. At high irradiation power, a qualitative correspondence to a model including a 4 π -periodic component to the supercurrent is found.

scholarly journals Stopping power of a helium plasma under LTE or NLTE conditions

2018 ◽  
Vol 36 (4) ◽  
pp. 442-447
Author(s):  
Luis González-Gallego ◽  
Manuel D. Barriga-Carrasco ◽  
Juan Miguel Gil ◽  
Rafael Rodríguez ◽  
Guadalupe Espinosa
Keyword(s):  
Theoretical Model ◽  
Electron Temperature ◽  
Thermal Equilibrium ◽  
Stopping Power ◽  
Local Thermal Equilibrium ◽  
Helium Plasma ◽  
Slowing Down ◽  
Non Local ◽  
Argon Ions ◽  
Bound Electrons

AbstractIn this work, the stopping power of a partially ionized helium plasma due to its free and bound electrons is analyzed for an electron temperature and density in which local thermal equilibrium (LTE) or non-local thermal equilibrium (NLTE) regimes can be possible. In particular by means of collisional-radiative models, the average ionization of the plasma as well as the abundances of different helium species (HeI, HeII, and HeIII) are analyzed in both LTE and NLTE thermodynamic states. The influence of this ionization and of the different ion abundances on the stopping power of the helium plasma is shown to be quite significant. Finally, our theoretical model is compared with experimental results on slowing down of swift argon ions in helium plasma.

Observation of a.c. Josephson effect in gate tunable Josephson junction on topological insulator (Bi0.2Sb0.8)2 Te3 films

2019 ◽  
Author(s):  
Yuusuke Takeshige ◽  
Sadashige Matsuo ◽  
Russell Stewart Deacon ◽  
Kento Ueda ◽  
Yosuke Sato ◽  
...  
Keyword(s):  
Josephson Junction ◽  
Topological Insulator ◽  
Josephson Effect

scholarly journals Catalyst Ammonia Storage Measurements Using Radio Frequency Sensing

2017 ◽  
Author(s):  
Jonathan Aguilar ◽  
Leslie Bromberg ◽  
Alexander Sappok ◽  
Paul Ragaller ◽  
Jean Atehortua ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Electromagnetic Waves ◽  
Catalytic Reduction ◽  
Cavity Resonator ◽  
Wide Frequency Range ◽  
Scr Catalyst ◽  
Ammonia Storage ◽  
Catalyst Temperature ◽  
Rf Antenna ◽  
Rf Signal

Motivated by increasingly strict NOx limits, engine manufactures have adopted selective catalytic reduction (SCR) technology to reduce engine-out NOx below mandated levels. In the SCR process, nitrogen oxides (NOx) react with ammonia (NH3) to form nitrogen and water vapor. The reaction is influenced by several variables, including stored ammonia on the catalyst, exhaust gas composition, and catalyst temperature. Currently, measurements from NOx and/or NH3 sensors upstream and downstream of the SCR are used with predictive models to estimate ammonia storage levels on the catalyst and control urea dosing. This study investigated a radio frequency (RF) -based method to directly monitor the ammonia storage state of the SCR catalyst. This approach utilizes the SCR catalyst as a cavity resonator, in which an RF antenna excites electromagnetic waves within the cavity to monitor changes in the catalyst state. A mmonia storage causes changes in the dielectric properties of the catalyst, which directly impacts the RF signal. Changes in the RF signal relative to stored a mmonia (NH3) were evaluated over a wide frequency range as well as temperature and exhaust conditions. The RF response to NH3 storage, desorption, and oxidation on the SCR was observed to be well-correlated with changes in the catalyst state. Calibrated RF measurements demonstrate the ability to monitor the adsorption state of the SCR to within 10 % of the sensor full scale. The results indicate direct measurement of SCR ammonia storage levels, and resulting catalyst feedback control, via RF sensing to have significant potential for optimizing the SCR system to improve NOx conversion and decrease urea consumption.

Identification of Wireless Devices From Their Physical Layer Radio-Frequency Fingerprints

2018 ◽  
pp. 6136-6146
Author(s):  
Gianmarco Baldini ◽  
Gary Steri ◽  
Raimondo Giuliani
Keyword(s):  
Radio Frequency ◽  
Research Work ◽  
Main Idea ◽  
Physical Layer ◽  
Manufacturing Processes ◽  
Wireless Devices ◽  
Electronic Circuits ◽  
Rf Components ◽  
Wireless Device ◽  
Rf Signal

Extensive research has been performed in recent years for the identification of wireless devices from their radio frequency (RF) emissions. The main idea of identifying a wireless device through its RF emissions is that the electronic circuits and the RF components have specific characteristics determined by the production and manufacturing processes. These characteristics, which result in unique differences, can be used to distinguish a wireless device from another because they appear as subtle modification of the RF signal in space even if the wireless device generates a signal conformant to the standard. This chapter describes the main techniques for the fingerprinting of wireless devices using their RF transmission. There are still however some key challenges to overcome. This chapter tries to identify them in this context as well as providing possible approaches to solve them. Further research work is needed to investigate the portability issues between fingerprints taken using different receivers, as well as to identify and remove potential other sources of bias.

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