Spintronics news and resources

Ron Jansen from the Spintronics Research Center at the National Institute for Advanced Industrial Science and Technology (AIST) gives an interesting lecture about recent progress in silicon spintronics:

Researcher Michel de Jong of the NanoElectronics group (MESA+) in the University of Twente (Netherlands) received a €1.5 million grant from the European Research Council to fund his Spintronics work (this is his second ERC grant). Michel de Jong is focusing on organic materials, in particular in Buckyballs (spherical C60 molecules held together by weak bonds) sandwiched between two magnetic materials.

Michel explains that these molecules have very little effect on electron spin, which is a great advantage as it enables them to store spin information for much longer periods of time than silicon. Buckyballs have also been used to create Graphene Quantum Dots.

In the holidays and end-of-the-year spirit, here are the top 10 stories posted on Spintronics-Info in 2011, ranked by popularity (i.e. how many people read the story):

1. Dilute ferromagnetic oxide materials can be used in spintronic devices (Apr 24)
2. Electron spin-splitting (Rashba effect) shown in Bismuth selenide (Aug 21)
3. AMSC (MEMS and Spintronics company) on its way to the NASDAQ (Jun 20)
4. Electrical conductivity in magnetoresistive devices (Jan 31)
5. KEIO Spintronics Research Center introduction video (Feb 4)
6. High temperature electrical injection, detection and precession of spin accumulation in silicon (May 6)
7. David Awschalom: "Spintronics, Abandoning Perfection for the Quantum Age" (Feb 21)
8. Researchers develop new room-temperature Spintronic transistors (Mar 23)
9. DNA molecules can detect spin (Apr 1)
10. Atomtronics could be more powerful than electronics or spintronics (Mar 1)

Here's for an awesome 2012. May you all enjoy the holidays!

Tohoku University and Tokyo Electron announced that they will jointly develop Spintronics memory integration and manufacturing technology. Professor Tetsuo Endoh from Tohoku's Center for Spintronics Integrated Systems (CSIS) will lead the research. The aim of this project is to present a miniature highly-integrated Spintronics memory device and the process technologies needed to commercially manufacture it.

The CSIS is considered one of the world's leaders in Spintronics memory, and will contribute its magnetic material technologies, device technologies and design technologies. TEL will contribute process and equipment technologies. Here's a video showing the Spintronics IC work done at the CSIS:

MIT researchers showed that laser can be used to observe electrons spin and even control the electrons movement using polarization. This could lead to a very fast spintronics devices.

The team devised a method that can provide a detailed three-dimensional mapping of the electron energy, momentum and spin states all at once. They did this by using short, intense pulses of circularly polarized laser light whose time of travel can be precisely measured. Using this method they were able to image how the spin and motion are related, for electrons travelling in all different directions and with different momenta, all in a fraction of the time it would take using alternative methods.

Researchers from China's Fudan University say that graphene nanoribbons could potentially be used to create spin valves. They present a theoretic spin valve design that uses two hexagonal graphene "nanoislands" with zig-zag edges, which serve as the magnetic layers in the spin valve, connected by an armchair-type nanoribbon as the non-magnetic layer, through which the electrons can pass depending on the relative alignment of the spins in the nanoislands.

They calcualte that this design enables stable spin configurations at certain energies, and there will be stable configurations in which the islands are polarized either parallel or antiparallel with respect to each other — a necessary requirement for a spin valve.

This book discusses two ideas of using individual metal organic molecules in applications for data storage. The first is using metal-free phthalocyanine form a GMR contact consisting of one single molecule leading to the world smallest magnetic sensor. The second idea is using chromium acetylacetonate to study the properties of magnetic molecules adsorbed on surfaces in order to build magnetic bits for date storage.

Amazon link: 

Spintronics with individual metal-organic molecules

Researchers from the Trinity College in Dublin, Ireland, found out that Organic molecules can exhibit n-type magnetism. They say that conjugated polymers make strong candidates for future spintronic applications.

While organic compounds are interesting for spintronics due to their extremely long spin lifetimes (because of weak spin relaxation effects), it's not very easy to manipulate the spin orientation in organic spin devices. The new class of molecules (known as spin crossover compounds) may solve this issue as their spin state can be changed from low spin to high spin by an external perturbation.

Researchers from the Physical and Technical Institute in Braunschweig, Germany have discovered that waste heat can be used inside magnetic tunnel structures (such as those used in MRAM chips). This means that such structures may be used to monitor and control "thermoelectric voltages" and currents in highly integrated electronic circuits.

In their experiments, the scientists generated a temperature difference between the two magnetic layers and investigated the electric voltage (or "thermoelectric voltage") generated hereby. It turned out that the thermoelectric voltage depends on the magnetic orientation of the two layers nearly as strongly as the electric resistance. By switching the magnetization, it is therefore possible to control the thermoelectric voltage and, ultimately, also the thermal current flowing through the specimen.

New South Wales university (UNSW) announced that they completed and installed their new $1 million Vector Field Facility (VFF) equipment (which took them 5 years to develop and make). This is the world's largest cryogen-free vector magnet system. The VFF will be used to study and develop spintronic and quantum devices, quantum dots, self-assembled nanowires and more.

The VFF can enable very low temperature (0.01 degrees above absolute zero) and apply magnetic fields in any direction.