JOSEPHSON JUNCTION NETWORK AS A TOOL TO SIMULATE INTERGRAIN SUPERCONDUCTING CHANNELS IN YBCO FILMS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3068-3073 ◽  
Author(s):  
G. ROTOLI ◽  
C. DE LEO ◽  
G. GHIGO ◽  
L. GOZZELINO ◽  
C. CAMERLINGO
Keyword(s):  
Magnetic Field ◽  
Josephson Junction ◽  
Transport Properties ◽  
Granular Structure ◽  
Current Dependence ◽  
Josephson Junction Network ◽  
Experimental Findings ◽  
Static Conditions ◽  
Vortex Phases ◽  
The Magnetic Field

Recent considerations on the physics of YBa 2 Cu 3 O 7-δ films made possible explaining their transport properties as flow of supercurrents through links between the granular structure of the film. The present work deals with the analysis of the Josephson junction network as a discrete set of parallel junctions (1D array) in quasi-static conditions and is aimed to compare the results of the simulations with the experimental findings, in particular with the plateau-like features in the critical current dependence on the magnetic field. Different regimes and vortex phases have been individuated and discussed.

SUPERCONDUCTIVITY ASSOCIATED WITH THE GRANULAR STRUCTURE IN Ba2YCu3O7−δ

1988 ◽  
Vol 02 (08) ◽  
pp. 1011-1015
Author(s):  
YONG ZHAO ◽  
QIRUI ZHANG ◽  
WEIYAN GUAN ◽  
JIANSHENG XIA ◽  
ZHENHUI HE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Single Phase ◽  
Granular Structure ◽  
Current Voltage ◽  
Granular Superconductivity ◽  
Current Voltage Characteristics ◽  
The Magnetic Field ◽  
Nonmonotonic Behavior

The dependence of the resistance on the magnetic field and the current-voltage characteristics of the single phase Ba 2 YCu 3 O 7−δ have been measured. The nonmonotonic behavior and a hysteresis of R(H) and the current-voltage characteristics suggest that the granular superconductivity exist in this material, and it plays an important role in transport properties.

scholarly journals Effect of confinement potential shape on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot at finite temperature

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
K. Luhluh Jahan ◽  
Bahadir Boyacioglu ◽  
Ashok Chatterjee
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Quantum Dot ◽  
Transport Properties ◽  
Average Energy ◽  
Persistent Current ◽  
Confinement Potential ◽  
Potential Shape ◽  
Gaas Quantum Dot ◽  
The Magnetic Field

Abstract The effect of the shape of the confinement potential on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot is studied using the power-exponential potential model with steepness parameter p. The average energy, heat capacity, magnetic susceptibility and persistent current are calculated using the canonical ensemble approach at low temperature. It is shown that for soft confinement, the average energy depends strongly on p while it is almost independent of p for hard confinement. The heat capacity is found to be independent of the shape and depth of the confinement potential at low temperatures and for the magnetic field considered. It is shown that the system undergoes a paramagnetic-diamagnetic transition at a critical value of the magnetic field. It is furthermore shown that for low values of the potential depth, the system is always diamagnetic irrespective of the shape of the potential if the magnetic field exceeds a certain value. For a range of the magnetic field, there exists a window of p values in which a re-entrant behavior into the diamagnetic phase can occur. Finally, it is shown that the persistent current in the present quantum dot is diamagnetic in nature and its magnitude increases with the depth of the dot potential but is independent of p for the parameters considered.

SUPERCONDUCTING FILM WITH AN ARRAY OF MAGNETIC NANOSTRIPES

2013 ◽  
Vol 27 (15) ◽  
pp. 1362020 ◽  
Author(s):  
K. KIM ◽  
K. K. D. RATHNAYAKA ◽  
I. F. LYUKSYUTOV ◽  
D. G. NAUGLE
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Critical Current ◽  
Film Surface ◽  
Critical Currents ◽  
Superconducting Film ◽  
Insulating Layer ◽  
Field Effects ◽  
Matching Field ◽  
The Magnetic Field

We present studies of the transport properties of a Sn superconducting film with an array of parallel nickel magnetic nanostripes (800 nm period) deposited on top of a germanium insulating layer covering the Sn film surface. The critical current parallel to the stripes is larger than the critical current perpendicular to the stripes. Both critical currents demonstrate strong hysteresis and matching field effects. We have observed strong hysteresis in the resistance dependence on the magnetic field.

Using electrochemical fabrication to grow external arrays of magnetic nanostripes to manipulate superconductivity in the thin film

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542036
Author(s):  
Wonbae Bang ◽  
W. Teizer ◽  
K. K. D. Rathnayaka ◽  
I. F. Lyuksyutov ◽  
D. G. Naugle
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Transport Properties ◽  
Electrochemical Fabrication ◽  
The Magnetic Field

We present results on electrochemical fabrication of arrays of magnetic nanostripes atop a Sn film covered with an insulating Ge layer. We also report its transport properties and superconducting [Formula: see text]. The transport properties demonstrate strong hysteresis as a function of the magnetic field.

scholarly journals Taming the Janssen effect

2021 ◽  
Vol 249 ◽  
pp. 08004
Author(s):  
Louison Thorens ◽  
Knut Jørgen Måløy ◽  
Mickaël Bourgoin ◽  
Stéphane Santucci
Keyword(s):  
Magnetic Field ◽  
Radial Force ◽  
Dipole Interactions ◽  
Full Control ◽  
Grain Packing ◽  
Experimental Findings ◽  
The Magnetic Field ◽  
Measured Mass ◽  
Granular Column ◽  
True Mass

We investigate both experimentally and theoretically the apparent mass of a ferromagnetic granular assembly filling a cylindrical container and submitted to a magnetic field B, aligned vertically along the silo. We show that the mass of the ferromagnetic granular column depends strongly on the applied magnetic field. Notably, our measurements deviate strongly from the exponential saturation of the measured mass as a function of the true mass of the grain packing, as predicted by Janssen [H.A. Janssen, Vereins Eutscher Ingenieure Zeitschrift, 1045 (1895)]. In particular, the measured mass of tall columns decreases systematically as the amplitude of the magnetic field increases. We rationalize our experimental findings by considering the induced magnetic dipole-dipole interactions within the whole packing. We show the emergence of a global magnetic radial force along the walls of the silos, fully determined by the external magnetic field. The resulting tunable frictional interactions allows a full control of the effective mass of the ferromagnetic granular column.

scholarly journals Remarks on the Transport Properties of a Fully Ionized Gas with Application to a Radially Constricted Gas Discharge

1963 ◽  
Vol 16 (2) ◽  
pp. 216 ◽  
Author(s):  
PW Seymour
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Hydrogen Isotope ◽  
High Field ◽  
Gas Discharge ◽  
Ionized Gas ◽  
The Magnetic Field ◽  
Thermal Conductivities ◽  
Vaughan Williams

The correction of Vaughan-Williams and Haas to Marshall's l set of thermal conductivities for a fully ionized hydrogen isotope in the presence of a magnetic field is extended to thel?. and �q (or K) sets, and the high-field limits for the components perpendicular to the magnetic field are included.

The Quantuam Melting Transitions with the Magnetic Field in Weakly Disordered Josephson Junction Arrays

2013 ◽  
Vol 380-384 ◽  
pp. 4845-4848
Author(s):  
Zhi Gang Zhao ◽  
Cun Li Dai ◽  
Lun Wu Zeng
Keyword(s):  
Magnetic Field ◽  
Josephson Junction ◽  
Vortex System ◽  
Josephson Junction Arrays ◽  
Melting Transitions ◽  
Dynamic Melting ◽  
Junction Arrays ◽  
The Magnetic Field ◽  
A Current ◽  
Moving Vortex

Using the resistively shunted junction model, we study the magnetic field induced dynamic melting transitions of a current-driven vortex system in two-dimensional weakly disordered Josephson junction arrays at zero temperature. From the unified model simulations, we find that the intrinsic quantum vortex liquid (QVL) phenomenon, which consistent with the recent experimental reports in disordered and superconducting MoGe films. The enhancement of critical current in the QVL phase arises from intrinsic quantum fluctuations in the moving vortex flow.

NUMERICAL STUDY OF TRANSPORT PROPERTIES IN TOPOLOGICAL INSULATOR QUANTUM DOTS UNDER MAGNETIC FIELD

2013 ◽  
Vol 27 (14) ◽  
pp. 1350104 ◽  
Author(s):  
SHENG-NAN ZHANG ◽  
HUA JIANG ◽  
HAIWEN LIU
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Transport Properties ◽  
Topological Insulator ◽  
Numerical Study ◽  
Spin Polarized ◽  
Full Band ◽  
Spin Degeneracy ◽  
Aharonov Bohm ◽  
The Magnetic Field

In this paper, we investigate the transport properties of HgTe / CdTe -based topological insulator quantum dots (TIQDs) under magnetic field. Both disk and square shaped TIQDs are considered and the magneto-conductance are calculated numerically for various magnetic field strength. The magnetic field lifts the spin degeneracy, leading to spin polarized current at given Fermi energy. Meanwhile, the magneto-conductance demonstrates the Aharonov–Bohm (AB) oscillation with a period of one flux quantum [Formula: see text]. Numerical results for AB oscillation features indicate the mismatch between electron (e) and hole (h) doping conditions, which can be attributed to the e–h asymmetry in the full band Hamiltonian. Further, interference effect emerges around bulk and edge energy degenerate points, subsequently suppressing the magneto-conductance in both shaped systems. All these physical characteristics are qualitatively consistent for disk and square shaped TIQDs due to the topological nature of edge modes.

SUPERCONDUCTING FILM WITH EMBEDDED COBALT NANORODS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362005 ◽  
Author(s):  
H. LEE ◽  
K. KIM ◽  
K. K. D. RATHNAYAKA ◽  
I. F. LYUKSYUTOV ◽  
D. G. NAUGLE
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Critical Current ◽  
Triangular Array ◽  
Unit Cell ◽  
Superconducting Film ◽  
Integral Number ◽  
Control Film ◽  
The Magnetic Field

Studies of the transport properties of a PbBi superconducting film with an embedded triangular array of cobalt nanorods with a 300 nm period are reported. It is found that the critical current demonstrates strong hysteresis and maxima at magnetic field values corresponding to an integral number of flux quanta per unit cell of the array. The amplitude of the critical current is larger than for a control film without nanorods. The increase varies from several times to several orders of magnitude depending on the magnetic field and temperature.

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