Magnetic memory design breakthrough can lead to faster computers

January 11, 2006
Magnetic memory design breakthrough can lead to faster computers

Fig. 1: Top view scanning electron microscope (SEM) micrographs of (a) symmetric and (b) asymmetric nanorings fabricated from /r/ = 50 nm PS spheres at 0° and 14° / /ion milling angles, respectively. Inset is the composition sensitive SEM image of the ring, bright areas represent Co.

Imagine a computer that doesn't lose data even in a sudden power outage, or a coin-sized hard drive that could store 100 or more movies. Magnetic random-access memory, or MRAM, could make these possible, and would also offer numerous other advantages. It would, for instance, operate at much faster than the speed of ordinary memory but consume 99 percent less energy.

The current challenge, however, is the design of a fast, reliable and inexpensive way to build stable and densely packed magnetic memory cells.

Magnetic memory design breakthrough can lead to faster computers

Fig. 2: SEM image of 100 nm symmetric Co nanorings released from substrates that tend to bundle together due to magnetic attraction.

A team of researchers at The Johns Hopkins University, writing in the Jan. 13 issue of Physical Review Letters, has come up with one possible answer: tiny, irregularly shaped cobalt or nickel rings that can serve as memory cells. These "nanorings" can store a great quantity of information. They also are immune to the problem of "stray" magnetic fields, which are fields that "leak" from other kinds of magnets and can thus interfere with magnets next to them.

"It's the asymmetrical design that's the breakthrough, but we are also very excited about the fast, efficient and inexpensive method we came up with for making them," said paper co-author Frank Q. Zhu, a doctoral candidate in the Henry A. Rowland Department of Physics and Astronomy in the Krieger School of Arts and Sciences at Johns Hopkins.

The nanorings are extremely small, with a diameter of about 100 nanometers. A single nanometer is one billionth of a meter. A single strand of human hair can hold 1 million rings of this size, Zhu says.

The asymmetrical design allows more of the nanorings to end up in a so-called "vortex state," meaning they have no stray field at all. With no stray field to contend with, Zhu's team's nanorings act like quiet neighbors who don't bother each other and, thus, can be packed together extremely densely. As a result, the amount of information that can be stored in a given area is greatly increased.

Fabrication of the nanorings is a multistep procedure involving self-assembly, thin film deposition and dry etching. The key to creating the irregular rings, Zhu said, is to -- while etching the rings with an argon ion beam at the end of the process -- tilt the substrate on which the rings are formed.

"In our previous study, we found that 100 nanometer symmetric nanorings have only about a 40 percent chance to get vortex state," Zhu said. "But the asymmetric nanorings have between a 40 percent and 100 percent chance to get vortex state. This chance can be controlled on-demand by utilizing the direction of magnetic field."

Source: Johns Hopkins University

4.4 /5 (50 votes)  

Rank 4.4 /5 (50 votes)
Tags

Related Stories
Relevant PhysicsForums posts

More news stories

Hovering not hard if you're top-heavy, researchers find

Top-heavy structures are more likely to maintain their balance while hovering in the air than are those that bear a lower center of gravity, researchers at New York University's Courant Institute of Mathematical Sciences ...

Physics / General Physics

created just added | popularity not rated yet | comments 0 | with audio podcast

SLAC, Stanford team focuses on high-energy electrons to treat cancer

Accelerator physicists at SLAC and cancer specialists from Stanford are working on a new technology that could dramatically reduce the time needed for cancer radiation treatments. The team ran an initial experiment ...

Physics / General Physics

created 3 hours ago | popularity not rated yet | comments 0

Measurements from high-energy collisions lead to better understanding of why meson particles disappear

For several years, physicists at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), USA, have studied an unusual state of matter called the quark–gluon plasma, which they ...

Physics / General Physics

created 3 hours ago | popularity not rated yet | comments 0

Quantum physicist explains $100K offer for proof scaled-up quantum computing is impossible

(PhysOrg.com) -- MIT researcher Scott Aaronson has certainly riled the physics community with his offer this past Friday, of $100,000 to anyone who can prove that scaled-up quantum computing is impossible. ...

Physics / Quantum Physics

created Feb 08, 2012 | popularity 4.1 / 5 (11) | comments 32 | with audio podcast weblog

Explained: Sigma

It's a question that arises with virtually every major new finding in science or medicine: What makes a result reliable enough to be taken seriously? The answer has to do with statistical significance -- but ...

Physics / General Physics

created Feb 09, 2012 | popularity 5 / 5 (14) | comments 26


New understanding of DNA repair could eventually lead to cancer therapy

A research group in the Faculty of Medicine & Dentistry at the University of Alberta is hoping its latest discovery could one day be used to develop new therapies that target certain types of cancers.

Zuckerberg's focus drives Facebook's ascent

When Mark Zuckerberg showed up to rent Judy Fusco's Los Altos, Calif., house in the fall of 2004, soon after he'd arrived in Silicon Valley, the landlord was immediately struck by his confidence.

Both maternal and paternal age linked to autism

Older maternal and paternal age are jointly associated with having a child with autism, according to a recently published study led by researchers at The University of Texas Health Science Center at Houston (UTHealth).

Night, weekend delivery OK for babies with birth defects

Weekday delivery is no better than night or weekend delivery for infants with birth defects, according to a new study presented today at The Pregnancy Meeting, the Society for Maternal-Fetal Medicine's annual conference. ...

Sonic Cradle lands spot in TED exhibition

A Simon Fraser University graduate student project that melds music, meditation and modern technology has landed a rare spot as an exhibit at TEDActive 2012 in Palm Springs, California this month.

Drug halts organ damage in inflammatory genetic disorder

A new study shows that Kineret (anakinra), a medication approved for the treatment of rheumatoid arthritis, is effective in stopping the progression of organ damage in people with neonatal-onset multisystem inflammatory disease ...