Data processing at the speed of light

Wednesday, 12 February, 2014
As our increasingly computer-driven world creates more and more data, the need for enhanced processing power to store, retrieve and analyse that data is significantly growing.

In fields ranging from science and medicine to finance and business, security and defence, it is now commonplace to talk about ‘big data’ and the challenge of managing such vast quantities of information. It is a challenge that is already starting to exceed the capabilities of existing technology, since the processing speeds that are possible using conventional magnetic fields to store and retrieve data on media such as hard discs are approaching their limits.

The EU-funded project ULTRAMAGNETRON investigated radical new ways of improving data handling speeds. The focus of the research team’s approach was on developing ways of controlling magnetic storage using light rather than magnetic fields, as it was the case in the past. Given that a laser pulse is one of the shortest man-made events ever devised, with ultrafast lasers now operating in the terahertz (THz) range – in other words, at trillions of cycles per second - the use of this technology was seen as a promising avenue to explore.

The key aspect determining the performance of magnetic storage media is not the original saving of the data but the ‘reading back’ of it - the speed of access and retrieval of that data by a process known as ‘magnetisation reversal’. Here, the ULTRAMAGNETRON team was working with concepts of speed that are little short of mind-boggling to an outsider. From magnetisation reversal speeds currently measured in nanoseconds, or thousandths of a millionth of a second, ULTRAMAGNETRON’s aim was to move it into the realm of picoseconds - millionths of one millionth of a second.

That difference may not sound much – until you realise what that single order of magnitude actually means in practice. While the relationship between a nanosecond and a second is equivalent to one second in 31.7 years, the relationship between a picosecond and a second is the equivalent of a single second in 31,700 years. Such was the scale of the challenge facing the ULTRAMAGNETRON team.

Working at the cutting edge of ‘opto-nano-magnetism’, investigating ways of using light to manipulate the magnetic properties of nanomaterials, ULTRAMAGNETRON’s researchers achieved major advances. These included the discovery of methods to perform magnetisation reversal at speeds of less than 100 picoseconds, using structures of below 200 nanometres in size. But the progress did not stop there. Quite remarkably, the team went on to discover ways of using laser control of nanomagnetism to achieve magnetisation reversal faster than a single picosecond.

In the words of ULTRAMAGNETRON’s Project Coordinator, Professor Theo Rasing of Radboud University, Nijmegen, in The Netherlands: “This was a truly novel approach developed by the research team which could not have even been predicted before the project started.”

The potential advances opened up by ULTRAMAGNETRON’s work could lead to a revolution in the field of data storage and usage. “Data storage is driven by two demands – higher speed and higher density,” says Professor Rasing. “In addition, the energy consumption of data storage and manipulation is becoming a major issue. Optical manipulation using ultrafast lasers could be the answer to all these problems.”

Since the official end of the project in 2011, work to build on the remarkable results of ULTRAMAGNETRON has continued. “A patent has been filed, and a demonstrator model is now being developed,” comments Professor Rasing.
There is no doubt that the world needs the capability to handle its exponentially increasing volumes of data - rather than collapse under the sheer weight of it. Thanks to the work of ULTRAMAGNETRON team, the ultrafast technology needed, allowing data storage and retrieval at speeds never achieved before, could soon be within our reach.    

Ultrafast all-optical magnetization reversal for magnetic recording and laser-controlled spintronics
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