GEOMETRICAL BARRIER IN A SUPERCONDUCTING STRIP: SINGLE-VORTEX APPROACH

2004 ◽  
Vol 18 (01) ◽  
pp. 19-26 ◽  
Author(s):  
A. A. ELISTRATOV ◽  
O. A. BOBRIKOV ◽  
I. L. MAKSIMOV ◽  
V. JEUDY

The problem of the geometrical barrier is solved for the vortex fragment entering from the corners of a superconducting strip, placed into a perpendicular magnetic field. A single-vortex Gibbs potential is constructed for the first time taking into account the actual current/field distribution in a sample of rectangular cross-section. The dependence of the vortex inclination angle as well as the vortex altitude on the external magnetic field is determined. Geometrical barrier-suppression field is found at which near-the-edge vortices start penetrating deep into the strip.

2000 ◽  
Vol 62 (1) ◽  
pp. 115-118 ◽  
Author(s):  
R. Prozorov ◽  
R. W. Giannetta ◽  
A. Carrington ◽  
F. M. Araujo-Moreira

2015 ◽  
Vol 15 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Matthias Ratajczak ◽  
Thomas Wondrak ◽  
Klaus Timmel ◽  
Frank Stefani ◽  
Sven Eckert

AbstractIn continuous casting DC magnetic fields perpendicular to the wide faces of the mold are used to control the flow in the mold. Especially in this case, even a rough knowledge of the flow structure in the mold would be highly desirable. The contactless inductive flow tomography (CIFT) allows to reconstruct the dominating two-dimensional flow structure in a slab casting mold by applying one external magnetic field and by measuring the flow-induced magnetic fields outside the mold. For a physical model of a mold with a cross section of 140 mm×35 mm we present preliminary measurements of the flow field in the mold in the presence of a magnetic brake. In addition, we show first reconstructions of the flow field in a mold with the cross section of 400 mm×100 mm demonstrating the upward scalability of CIFT.


2008 ◽  
Vol 22 (12) ◽  
pp. 1923-1932
Author(s):  
JIA LIU ◽  
ZI-YU CHEN

The influence of a perpendicular magnetic field on a bound polaron near the interface of a polar–polar semiconductor with Rashba effect has been investigated. The material is based on a GaAs / Al x Ga 1-x As heterojunction and the Al concentration varying from 0.2 ≤ x ≤ 0.4 is the critical value below which the Al x Ga 1-x As is a direct band gap semiconductor.The external magnetic field strongly altered the ground state binding energy of the polaron and the Rashba spin–orbit (SO) interaction originating from the inversion asymmetry in the heterostructure splitting of the ground state binding energy of the bound polaron. How the ground state binding energy will be with the change of the external magnetic field, the location of a single impurity and the electron area density have been shown in this paper, taking into account the SO coupling. The contribution of the phonons are also considered. It is found that the spin-splitting states of the bound polaron are more stable, and, in the condition of weak magnetic field, the Zeeman effect can be neglected.


2016 ◽  
Vol 7 ◽  
pp. 990-994 ◽  
Author(s):  
Xiaoyu Li ◽  
Lijuan Sun ◽  
Hu Wang ◽  
Kenan Xie ◽  
Qin Long ◽  
...  

In contrast to the majority of related experiments, which are carried out in organic solvents at high temperatures and pressures, cobalt nanowires were synthesized by chemical reduction in aqueous solution with the assistance of polyvinylpyrrolidone (PVP) as surfactant under moderate conditions for the first time, while an external magnetic field of 40 mT was applied. Uniform linear cobalt nanowires with relatively smooth surfaces and firm structure were obtained and possessed an average diameter of about 100 nm with a coating layer of PVP. By comparison, the external magnetic field and PVP were proven to have a crucial influence on the morphology and the size of the synthesized cobalt nanowires. The prepared cobalt nanowires are crystalline and mainly consist of cobalt as well as a small amount of platinum. Magnetic measurements showed that the resultant cobalt nanowires were ferromagnetic at room temperature. The saturation magnetization (M s) and the coercivity (H c) were 112.00 emu/g and 352.87 Oe, respectively.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 713
Author(s):  
Siya Lozanova ◽  
Ivan Kolev ◽  
Avgust Ivanov ◽  
Chavdar Roumenin

A novel in-plane sensitive Hall arrangement consisting of two identical n-Si three-contact (3C) elements and realized in a common technological process, is presented. In the solution, the minimization of the offset and its temperature drift is achieved by cross-coupling of the outer device contacts. This terminals’ connection provides equalizing currents between the two substrates which strongly compensate the inevitable difference in the electrical conditions in the two parts of the arrangement. As a result, the residual offset of both integrated Hall elements at the output Vout(0) and its temperature drift are strongly minimized. The residual offset is about 160 times smaller than the single-configuration one. The obtained output voltage-to-residual offset ratio at sensitivity of SRI ≈ 98 V/AT is very promising, reaching 6 × 103 at temperature T = 40 °C and induction 1 T. As a result, increased metrological accuracy for numerous applications is achieved. For a first time through the novel arrangement a suppression of sensitivity in the presence of external magnetic field could be achieved in order to obtain permanent offset information. This is one of the key results in the Hall device investigation.


2007 ◽  
Vol 21 (28) ◽  
pp. 1885-1893 ◽  
Author(s):  
L. REN

For a two-dimensional electron gas with equal Rashba and Dresselhaus spin-orbit coupling strength (ReD model), and the Dresselhaus [110] model, the influence of an external magnetic field on the lifetime of the Spin Helix (SH) has been considered. A perpendicular magnetic field has no influence on the lifetime of the SH for the Dresselhaus [110] model, independent of the strength of the magnetic field. But for the ReD model, when the magnetic field is weak, and we only take the linear term of the magnetic field B into account, the conclusion is still so. In addition, if the external magnetic field is in-plane with a suitable angle between the x and y component, the lifetime of the SH will also be infinite.


Author(s):  
Seung-Yeon Kim

<p>A ferromagnetic material in the absence of an external magnetic field shows the peak of its specific heat in low temperature, called the Schottky anomaly, which is vital in understanding the low-energy structure of a given material. A general formula for the low-temperature behavior of the specific heat of an N-spin ferromagnetic material in an external magnetic field (the generalized Schottky anomaly) is obtained for the first time. Also, as a representative example of ferromagnetic materials in an external magnetic field, the low-temperature behavior of the specific heat for the Ising ferromagnet is studied.</p>


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