UC Riverside, Russian Academy for Science produce holographic memory

Joint research out of UC Riverside and the Russian Academy for Science has produced a new type of holographic memory device utilizing spin waves. Their invention has the potential to make improvements to modern technology, including the benefits of increased storage and processing capacity that has never before been attainable.

The UC Riverside team is led by Professor Alexander Khitun, who has worked on spin wave-based technologies for over nine years. He, along with team member and UC Riverside graduate student Frederick Gertz, submitted their research for publication in the journal Applied Physics Letters on Jan. 21 of this year.

Spin waves are magnetic waves that are caused by an alternating magnetic field. They were used in order to increase memory capabilities, lower energy consumption and meet the requirements of today’s electrical components.

“If you throw two rocks into a pond at the same time, they will both create waves, and where these waves meet they will ‘interfere’ or cause the waves to change slightly. The same is true for our system. We can make two magnetic waves, whose interference pattern will change, based on the number of magnets and the direction that those magnets are facing that those waves encounter as they travel along their path,” Gertz said.

One instrumental feature of spin waves is accredited to their wavelength; shortening the wavelengths increases the number of bits that can be stored and processed. This is how the increase in memory capacity and capability is brought to life in their device.

“The utilization of spin waves allows us to reduce the operating wavelength to tens of nanometers. According to the estimates, magnonic holograms may have capacity up to 1Tb/cm2 due to their nanometer scale wavelength,” Khitun said.

Holography is a technique which creates three-dimensional images through the use of lasers; when the laser detects an object, it records the resulting light interference pattern created. Thus, holograms are inherently greater than standard photographs in terms of pure information, as they hold all angles of an object, rather than one.

“Since we are using a holographic technique it means that our spin waves can pass through several different magnets with different orientations and the output will tell us ALL of the magnet’s orientation. This allows us to build devices that can read out data very quickly, much quicker than a standard electronic design would allow,” Gertz said.

Due to spin waves’ innate low energy, this research has the potential to produce technology considerably more efficient than that presently employed. Such success could lower the energies of a wide range of technologies and provide a solution to lower the costly price of cooling large scale datacenters.

Professor Charles Fadley, a member of the UC Davis Physics Department, has recently worked with holographic imaging of atoms using a technique called photoelectron holography in his research.

“The research is very interesting, and the arguments they make for the possibility of future developments beyond the simple 2-bit device they have demonstrated are reasonable. But it’s difficult to say at this point whether real technological applications to data storage will result,” Fadley said.

The team’s research and improvements to their prototype are ongoing. Future developments include finding a superior material suitable for spin wave use, minimizing the size and energy in exciting spin waves and continued research of the potential of their device.

“The main objective of our work is to demonstrate a holographic co-processor, which can be integrated within the conventional digital processors … We also need to scale down the operating wavelength and make these devices smaller in order to build a practical device,” Khitun said.