THERMOELECTRIC EFFECTS IN MESOSCOPIC SUPERCONDUCTOR/FERROMAGNETIC JUNCTIONS

2007 ◽  
Vol 21 (32) ◽  
pp. 5381-5386 ◽  
Author(s):  
ATTIA A. AWAD ALLA ◽  
ADEL H. PHILLIPS
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Spin Polarization ◽  
Andreev Reflection ◽  
Spin Transport ◽  
Thermoelectric Effects ◽  
Thermoelectric Voltage ◽  
Mesoscopic Superconductor ◽  
Quantum Device ◽  
Heater Current

Spin transport properties of a mesoscopic superconductor/ferromagnetic (S/F) junctions of a quantum device are investigated. The thermoelectric voltage as a function of magnetic field oscillations for different heater currents has been calculated. The dependence shows that by increasing the heater current, the oscillation first disappears, and then remarkably reappears inverted compared to low heater current. Also, the value of the thermo-power increases with increasing value of the barrier strength. Our result shows that the degree of spin polarization of the current can be unambiguously determined using Andreev reflection. Our result agrees qualitatively with those in the literature.

The Spin Transport of the Coblt Dimers with Different Directions

2014 ◽  
Vol 543-547 ◽  
pp. 3947-3950
Author(s):  
Shi Wei Ren
Keyword(s):  
Transport Properties ◽  
Spin Polarization ◽  
Density Of States ◽  
Bias Voltage ◽  
Spin Transport ◽  
First Principle ◽  
Transport Direction ◽  
Spin Polarized ◽  
Analysis Calculation

In this paper, the spin transport properties of the coblt dimers parrallel to the transport direction and perpendicular to ransprot direction are investigated by using the first principle analysis. Calculation shows that both the coblt dimers parrallel to the transport direction and perpendicular to ransprot direction give obvious spin polarized density of states and current. It is found that the dimer parrallel to the transport direction have larger spin polarization current.The spin polarized efficiency for the parrallel dimer increase steadily with the increase of the bias voltage. But the the spin polarization for the transverse dimer changes greatly.

REEXAMINATION OF SPIN TRANSPORT THROUGH A DOUBLE-δ MAGNETIC BARRIER WITH SPIN-ORBIT INTERACTIONS

2009 ◽  
Vol 23 (30) ◽  
pp. 3631-3642
Author(s):  
CAIHUA BI ◽  
FENG ZHAI
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Spin Polarization ◽  
Energy Region ◽  
Spin Transport ◽  
Inhomogeneous Magnetic Field ◽  
Pure Spin ◽  
Spin Orbit ◽  
Spin Orbit Interactions ◽  
The Magnetic Field

We revisit the properties of spin transport through a semiconductor 2DEG system subjected to the modulation of both a ferromagnetic metal (FM) stripe on top and the Rashba and Dresselhaus spin-orbit interactions (SOIs). The FM stripe has a magnetization along the transporting direction and generates an inhomogeneous magnetic field in the 2DEG plane which is taken as a double-δ shape. It is found that the spin polarization of this system generated from a spin-unpolarized injection can be remarkable only within a low Fermi energy region and is not more than 30% for the parameters available in current experiments. In this energy region, both the magnitude and the orientation of the spin polarization can be tuned by the Rashba strength, the Dresselhaus strength, and the magnetic field strength. The magnetization reversal of the FM stripe cannot result in a change of the conductance, but can rotate the orientation of the spin polarization. The results are in contrast to those in [ J. Phys.: Condens. Matter15 (2003) L31] where a pure spin state for incident electrons is artificially assumed.

scholarly journals Topological isoconductance signatures in Majorana nanowires

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. S. Ricco ◽  
J. E. Sanches ◽  
Y. Marques ◽  
M. de Souza ◽  
M. S. Figueira ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Transport Properties ◽  
Spin Polarization ◽  
Bound States ◽  
Spin Asymmetry ◽  
Experimental Protocol ◽  
Zero Bias ◽  
Topological Superconductor ◽  
Hybrid Device ◽  
Majorana Bound States

AbstractWe consider transport properties of a hybrid device composed by a quantum dot placed between normal and superconducting reservoirs, and coupled to a Majorana nanowire: a topological superconducting segment hosting Majorana bound states (MBSs) at the opposite ends. It is demonstrated that if highly nonlocal and nonoverlapping MBSs are formed in the system, the zero-bias Andreev conductance through the dot exhibits characteristic isoconductance profiles with the shape depending on the spin asymmetry of the coupling between the dot and the topological superconductor. Otherwise, for overlapping MBSs with less degree of nonlocality, the conductance is insensitive to the spin polarization and the isoconductance signatures disappear. This allows to propose an alternative experimental protocol for probing the nonlocality of the MBSs in Majorana nanowires.

Electrical transport properties of FeSe single crystal under high magnetic field

2021 ◽  
Vol 64 (8) ◽  
Author(s):  
HongHui Wang ◽  
ZhaoHui Cheng ◽  
MengZhu Shi ◽  
DongHui Ma ◽  
WeiZhuang Zhuo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Transport Properties ◽  
High Magnetic Field ◽  
Electrical Transport ◽  
Electrical Transport Properties

scholarly journals Magnetic field amplification in newly-born neutron stars

1996 ◽  
Vol 160 ◽  
pp. 435-436
Author(s):  
H.-J. Wiebicke ◽  
U. Geppert
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Gravitational Collapse ◽  
Dipole Field ◽  
Numerical Calculations ◽  
Selection Effects ◽  
Thermoelectric Effects ◽  
Field Amplification ◽  
Seed Field ◽  
Flux Conservation

AbstractWe present a scenario of magnetic field (MF) evolution of newly-born neutron stars (NSs). Numerical calculations show that in the hot phase of young NSs the MF can be amplified by thermoelectric effects, starting from a moderately strong seed-field. Therefore, there is no need to assume a 1012G dipole field immediately after the gravitational collapse of the supernova (SN) event. The widely accepted scenario for such a field to be produced by flux conservation during the collapse is critically discussed. Instead, it can be generated by amplification and selection effects in the first 104yrs, and by the subsequent fast ohmic decay of higher multipole components, when the NS cools down.

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