Do you wish your computer was faster? Engineers and physicists from Germany have demonstrated the quickest prototype yet of an advanced form of RAM tipped by hardware manufacturers to be the future of computing. The device is so fast it brushes against a fundamental speed-limit for the process.

Magnetoresistive random access memory (MRAM) is a faster and more energy efficient version of the RAM used in computers today, and hardware companies think it will in a few years dominate the market. Its speed and low power will in particular boost mobile computing.

Whereas conventional RAM stores a digital 1 or 0 as the level of charge in the capacitor, MRAM stores it by changing the north-south direction of a tiny magnet’s magnetic field. Each variable magnet is positioned next to one with a fixed field. Reading a stored value involves running a current through the pair to discover the direction of the variable magnet’s field.
Spin flips

The MRAM that IBM and most other manufacturers are betting on uses the spins of electrons to flip the magnetic fields, called spin-torque MRAM.

Now researchers in Germany have built a spin-torque system that is dramatically faster than any other. Santiago Serrano-Guisan and Hans Schumacher of the Physical-Technical Federal Laboratory of Germany worked with University of Bielefeld and Singulus Nano-Deposition Technologies researchers to build it from tiny pillars 165 nanometres tall.

The top end of each pillar acts as a variable magnet that stores data, whereas the bottom ends are fixed magnets. A current passing through a pillar from bottom to top has the spin of its electrons lined up by the permanent-magnet region.

When those electrons reach the pillars’ other end, they flip the variable magnet region’s field to match. The field can be flipped back by reversing the current.

Usually when the field is flipped it takes some time to settle into its new orientation. The north-south axis draws a few circles in the air before settling into place.
Wobble control

But theoretical work says it needs to draw only one circle before finding its new position, making the process faster. The German team achieved that, developing a way to observe and control the field’s wobble during and after the flip.

By adjusting the duration and strength of the electrical pulse that flips the field, only a single “wobble” is allowed to take place, matching the theoretical limit.

The result is a device many times faster than any before. “Present MRAM are programmed by pulses of about 10 nanoseconds duration,” said Serrano-Guisan. “So we are ten times faster.” The very best conventional RAM needs around 30 nanoseconds for an equivalent operation.

Robert Buhrman, an expert in nanomagnetics at Cornell University, New York, is impressed but notes that a full MRAM device has not yet been made.

The current used by the German device is at present too electrically dense to be supplied by the transistors used in MRAM circuits. “The next thing that needs to be done is to get the switching currents down to a scale that is compatible with the [standard] CMOS (complementary metal–oxide–semiconductor) transistor,” said Buhrman.

Americans today spend almost as much on bandwidth – the capacity to move information – as we do on energy. A family of four likely spends several hundred dollars a month on cell phones, cable television and Internet connections, which is about what we spend on gas and heating oil.

Just as the industrial revolution depended on oil and other energy sources, the information revolution is fueled by bandwidth. If we aren’t careful, we’re going to repeat the history of the oil industry by creating a bandwidth cartel.

Like energy, bandwidth is an essential economic input. You can’t run an engine without gas, or a cell phone without bandwidth. Both are also resources controlled by a tight group of producers, whether oil companies and Middle Eastern nations or communications companies like AT&T, Comcast and Vodafone. That’s why, as with energy, we need to develop alternative sources of bandwidth.

Wired connections to the home – cable and telephone lines – are the major way that Americans move information. In the United States and in most of the world, a monopoly or duopoly controls the pipes that supply homes with information. These companies, primarily phone and cable companies, have a natural interest in controlling supply to maintain price levels and extract maximum profit from their investments – similar to how OPEC sets production quotas to guarantee high prices.

But just as with oil, there are alternatives. Amsterdam and some cities in Utah have deployed their own fiber to carry bandwidth as a public utility. A future possibility is to buy your own fiber, the way you might buy a solar panel for your home.

Encouraging competition is another path, though not an easy one: Most of the much-hyped competitors from earlier this decade, like businesses that would provide broadband Internet over power lines, are dead or moribund. But alternatives are important. Relying on monopoly producers for the transmission of information is a dangerous path.

After physical wires, the other major way to move information is through the airwaves, a natural resource with enormous potential. But that potential is untapped because of a false scarcity created by bad government policy.

Our current approach is a command and control system dating from the 1920s. The federal government dictates exactly what licensees of the airwaves may do with their part of the spectrum. These Soviet-style rules create waste that is worthy of Brezhnev.

Many “owners” of spectrum either hardly use the stuff or use it in highly inefficient ways. At any given moment, more than 90 percent of the nation’s airwaves are empty.

The solution is to relax the overregulation of the airwaves and allow use of the wasted spaces. Anyone, so long as he or she complies with a few basic rules to avoid interference, could try to build a better Wi-Fi and become a broadband billionaire. These wireless entrepreneurs could one day liberate us from wires, cables and rising prices.

Such technologies would not work perfectly right away, but over time clever entrepreneurs would find a way, if we gave them the chance. The Federal Communications Commission promised this kind of reform nearly a decade ago, but it continues to drag its heels.

In an information economy, the supply and price of bandwidth matters, in the way that oil prices matter: not just for gas stations, but for the whole economy.

And that’s why there is a pressing need to explore all alternative supplies of bandwidth before it is too late. Americans are as addicted to bandwidth as they are to oil. The first step is facing the problem.