An experiment carried out at the Physikalisch-Technische Bundesanstalt (PTB) has realized spin torque switching of a nanomagnet as fast as the fundamental speed limit allows. Using this so-called ballistic switching future non-volatile magnetic memories could operate as fast as the fastest non-volatile memories. The experiments are described in the next issue of Physical Review Letters (22 August, 2008.
Fast memory chips such as DRAMs and SRAMs (Dynamic and Static Random Access Memory) commonly used today have one decisive disadvantage: in case of power interruption, they lose their stored information. This problem could be solved by magnetic memory chips called MRAMs (Magnetic Random Access Memory). In MRAM the digital information is not stored by means of electric charge but by means of the orientation of the magnetization of a magnetic cell.
The latest generation of MRAM uses the so-called spin torque effect for programming the magnetic bits. Using spin torque the memory state of the cell can be programmed in a very simple way just by applying a current pulse. A positive current switches the magnetization to one direction (digital state "0") and a negative current to the other (digital state "1"). Spin torque MRAM further promise a high storage density comparable to DRAM and Flash. Most major semiconductor chip producers are developing spin torque memories and market introduction is expected, soon.
A spin torque current pulse excites a rotational motion of the magnetization of the memory cell - the so-called precession. Normally, the magnetization has to undergo several precessional turns before reliable magnetization reversal takes place. Therefore present spin torque MRAM prototypes must operate with rather long write pulses of about 10 nanoseconds duration which limits the MRAM clock speed.
In the experiment carried out at PTB Braunschweig spin torque magnetization reversal has now been realized by a single precessional turn, only. This so called "ballistic" spin torque magnetization reversal corresponds to the ultra short physical limit of spin torque magnetization reversal time. It was achieved by precise tailoring of the current pulse parameters in combination with a small magnetic bias field.
Using ballistic spin torque reversal future MRAM could be programmed by current pulses shorter than 1 nanosecond corresponding to write clock rates well above 1 GHz. It could thus enable a high-density and non-volatile memory operating at the clock rates of the fastest volatile memories.
Phone: +49531-592-2414, e-mail: firstname.lastname@example.org
Dr. Hans Werner Schumacher | EurekAlert!
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences