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D2 Physics www.spinelectronics.deD2 Physics www.spinelectronics.de
Simulation of GMR in granular C@Conanoparticles in agarose
P.Hainke, D.Kappe, A.Hütten
D2 Physics www.spinelectronics.de
The Giant Magnetoresistance (GMR) effect
• Electrical resistance dependentson switching on and off an outermagnetic field
• Spin dependent
D2 Physics www.spinelectronics.de
Spin channel currents
• Spin channel currents act like in aparallel circuit
• Therefore they can be described byvariegating the conductivity of theparticles
R↑= High resistance R↓= Low resitance
D2 Physics www.spinelectronics.de
GMR in granular gels
• Many different sizes of the magneticparticles
• No high ordered structure
But:• Particle chains in antiferromagnetic
order to the next neighbour
D2 Physics www.spinelectronics.de
Use of the Java API
Why Java?
• Automation of generatingmany particles
• Fast and flexible variationof space and size distribution
D2 Physics www.spinelectronics.de
Flexible geometry
Particles are variable inspace and size distribution
D2 Physics www.spinelectronics.de
Magnetic field via electric conductivity
Parametric sweep for the 3 conductivitiesdepending on the magnetic field
a) High and b) low conductivity in a magnetic fieldin contrast to c) the alternating conductivity withoutfield
D2 Physics www.spinelectronics.de
Results for a single chain
Can short chains show the effects of thein fact much longer chains?
Yes!Because the GMR in converges very fast
So no need of simulation of many elements
D2 Physics www.spinelectronics.de
Other geometries
Triangle 3 chains
Triangle 6 chains
Rhombus 4 chains
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Comparison
All geometries show similar curves
D2 Physics www.spinelectronics.de
Conclusion
• Flexible and fast generation of many elements, variable in size andspace distribution
• For simulation just short chains needed, because ΔR converges fast
• All geometries show similar curves
Simulation of variations in particle size and disordered spacedistribution
Thank you for your interest!