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P. Kampschroeder

Publications and source records attributed to P. Kampschroeder.

2 recordsLinked to original sources

Temperature Dependent Magnetism in Artificial Honeycomb Lattice of Connected Elements

Artificial magnetic honeycomb lattices are expected to exhibit a broad and tunable range of novel magnetic phenomena that would be difficult to achieve in natural materials, such as long-range spin ice, entropy-driven magnetic charge-ordered state and spin-order due to the spin chirality. Eventually, the spin correlation is expected to develop into a unique spin solid state density ground state, manifested by the distribution of the pairs of vortex states of opposite chirality. Here we report the creation of a new artificial permalloy honeycomb lattice of ultra-small connecting bonds, with a typical size of $\simeq$ 12 nm. Detail magnetic and neutron scattering measurements on the newly fabricated honeycomb lattice demonstrate the evolution of magnetic correlation as a function of temperature. At low enough temperature, neutron scattering measurements and micromagnetic simulation suggest the development of loop state of vortex configuration in this system.

cond-mat.mes-hall

Magnetic diode at $T$ = 300 K

We report the finding of unidirectional electronic properties, analogous to a semiconductor diode, in two-dimensional artificial permalloy honeycomb lattice of ultra-small bond, with a typical length of ~ 12 nm. The unidirectional transport behavior, characterized by the asymmetric colossal enhancement in differential conductivity at a modest current application of ~ 10-15 $μ$A, persists to T = 300 K in honeycomb lattice of thickness ~ 6 nm. The asymmetric behavior arises without the application of magnetic field. A qualitative analysis of experimental data suggests the role of magnetic charge or monopoles in the unusual observations with strong implication for spintronics.

cond-mat.mes-hall