2012-01-20

- Langmuir (2012)
The potential of metal nanoparticles (NPs) in electronic, optoelectronic, sensor, and biological applications is of great current interest. Therefore, the reproducible generation of versatile patterns of NPs is necessary in order to fabricate functional devices. A promising approach to fabricate such devices is the combination of lithographic techniques (top-down) and self-assembly processes of preformed, well-characterized metal NPs (bottom-up) on solid substrates. We report the formation of thiol nanopatterns on a self-assembled monolayer covered silicon wafers by converting sulfonic acid head groups via e-beam lithography. These thiol groups act as binding sites for gold nanoparticles, which can be enhanced to form electrically conducting nanostructures.

2012-01-13

- Phys. Rev. B 85, 012404 (2012)
The irreversible thermoremanent magnetization of a sole, magnetically diluted epitaxial antiferromagnetic Co_1−yO(100) layer is determined by the mean of its thermoremanent magnetizations at positive and negative remanence. During hysteresis-loop field cycling, the irreversible thermoremanent magnetization exhibits successive reductions, consistent with the training effect (TE) of the exchange bias measured for the corresponding Co_1−yO(100)/Co(1120) bilayer. The TE of exchange bias is shown to have its microscopic origin in the TE of the thermoremanent magnetization of the magnetically diluted antiferromagnet.

2011-11-16

- Alexander Nedilko was awarded with an RWTH-UGF project. He joined our group working on "optical generation of spin currents in graphene". Undergraduate funds are part of the RWTH Excellence Initiative

2011-09-20

- Semiconductor spintronics combines conventional semiconductor physics with magnetism to develop novel spin dependent nanoelectronic devices including devices for quantum information processing. Our institute contributes with one project in the last funding period of the priority project:
"Coherent spin transport in semiconductors"

2011-07-27

- Our institute is a project partner in the collaborative project “Nano-Workbench: extension of scanning electron and ion microscopes with nano-robotics and nano-analytics”. The project partners are:
1. Klocke Nanotechnik GmbH Aachen (website)
2. RWTH Aachen University
3. Ruhr-Universität Bochum (website)
4. RAITH GmbH Dortmund (website)
5. EO Elektronen-Optic Service GmbH (website)

2011-07-21

- Phys. Rev. Lett. 107, 047206 (2011)
Conventional electronic transistors involve the control of electronic charge at the nanoscale to realize memory, logic and communication functions. All these electronic charges, however, also carry a spin that remains unutilized in present commercial devices. Among the most promising materials for spintronics has been graphene, a truly two-dimensional crystal of carbon atoms. By fabricating spin valves on bilayer graphene (the two-layered cousin of graphene) we have achieved record room temperature spin relaxation times up to 2 nanoseconds. Furthermore, the presence of interlayer interaction between the two layers of bilayer graphene makes it a particularly profitable nanoscale material for spintronics – particularly since this interaction can be tuned by electric-field.

2011-06-09

- Spin polarized currents in magnetic nanostructures give rise to novel spin caloric effects. These effects modify thermal transport, magneto-resistance and possibly even magnetic states. The new Priority Programme "Spin Caloric Transport" aims to understand the observed effects, which requires to extend thermodynamic laws including the spin. Our institute contributes with one project:
"Spin Caloritronics in III-V semiconductors"

2011-05-12

- Nano Letters 11, 2363 (2011)
We demonstrate injection, transport, and detection of spins in spin valve arrays patterned in both copper based chemical vapor deposition (Cu-CVD) synthesized wafer scale single layer and bilayer graphene.We observe spin relaxation times comparable to those reported for exfoliated graphene samples demonstrating that chemical vapor deposition specific structural differences such as nanoripples do not limit spin transport in the present samples. Our observations make Cu-CVD graphene a promising material of choice for large scale spintronic applications.