Lyst på lysbasert minne til datamaskinen din?
Carlos Ríos, Matthias Stegmaier, Peiman Hosseini, Di Wang, Torsten Scherer, C. David Wright, Harish Bhaskaran & Wolfram H. P. Pernice
Nature Photonics (2015) doi:10.1038/nphoton.2015.182
Received 27 July 2015 Accepted 21 August 2015 Published online 21 September 2015
Implementing on-chip non-volatile photonic memories has been a long-term, yet elusive goal. Photonic data storage would dramatically improve performance in existing computing architectures1 by reducing the latencies associated with electrical memories2 and potentially eliminating optoelectronic conversions3. Furthermore, multi-level photonic memories with random access would allow for leveraging even greater computational capability4, 5, 6. However, photonic memories3, 7, 8, 9, 10 have thus far been volatile. Here, we demonstrate a robust, non-volatile, all-photonic memory based on phase-change materials. By using optical near-field effects, we realize bit storage of up to eight levels in a single device that readily switches between intermediate states. Our on-chip memory cells feature single-shot readout and switching energies as low as 13.4 pJ at speeds approaching 1 GHz. We show that individual memory elements can be addressed using a wavelength multiplexing scheme. Our multi-level, multi-bit devices provide a pathway towards eliminating the von Neumann bottleneck and portend a new paradigm in all-photonic memory and non-conventional computing.
Og en litt mer populærvitenskapelig framstilling av artikkelen:
September 22, 2015 | by Jonathan O'Callaghan
Researchers say they have developed a method to store data permanently in a memory chip using light. The breakthrough, published in the journal Nature Photonics, could lead to significantly faster computers in the future.
To store data, it is essential a device must be able to work when power is both on and off – think of a CD, DVD or hard drive. But computers are limited in their speed by the transmission of electric data between a processor and the memory stored in these devices – called the von Neumann bottleneck. This means that faster processors don't necessarily mean better computing power, when it is the transmission speed of the data that is the limiting factor.
Using light, or photons, to transfer data could therefore allow for much greater speeds. But until now, scientists had struggled to find a way to create a light-based device that can store data for a significant period of time.
“There’s no point using faster processors if the limiting factor is the shuttling of information to-and-from the memory,” said University of Oxford's Professor Harish Bhaskaran, who led the research, in a statement. “But we think using light can significantly speed this up.”
In this research, which also included the University of Münster, the Karlsruhe Institute of Technology and the University of Exeter, the team created the world’s first all-photonic non-volatile memory chip. It uses a material called Ge2Sb2Te5 (GST), which is also used in rewritable CDs and DVDs, to store data.