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At the edge of science: freezing bits

A terbium atom (red) is sandwiched between two organic molecules (grey and blue) to form a single-molecule magnet. Credit: Romain Vincent, Svetlana Klyatskaya, Mario Ruben, Wolfgang Werndorfer, and Franck Balestro

We are, collectively, producing an astounding amount of bits and there is no ending in sight to the growth. Google, in 2016, is storing bits in 15 data centres (as of 2016), managing 40 million searches per second through over 30 million servers (if you think about it is means a server answering about one search per second, which seems to be very little, but there is much much more running behind the scene that these servers are doing…).

Overall the energy used is impressive and so is the cost. No wonder that scientists al over the world are looking at ways to increase the storage density going beyond present technology.

A way to make a significant step forward would be to use single molecules to store a bit and scientists have already proved the technical feasibility, as an example using a terbium atom as a single magnet. The problem when you are scaling down to molecular level is the ambient “noise” that can alter the data, and noise at atomic level equals temperature. Researchers have been able to store a bit on a single molecule but they had to cool it down to a few degrees above absolute zero. This, in turns, requires a tremendous amount of power and in the end it would not solve the problem.

This is why the research published on Nature by scientists at University of Manchester is so interesting.

They found a composite material, hexa-tert-butyldysprosocenium complex, based on dysprosium (atomic number 66), that can have a good magnetic hysteresis cycle at 60 Kelvin (-213C). Having a good magnetic hystereses cycle is great: basically that it takes quite a bit of effort to change its magnetic orientation, which in turns ensure that if we store a data that data will remain stored and will not be affected by noise.

Now, -213 C still seems pretty cold, way beyond freezing. However it is within the freezing power of liquid nitrogen, and freezing with liquid nitrogen is way more cheaper than using liquid helium, which is what you would need to use to operate at atomic level with other materials.

It brings storage on single molecules within the range of economic feasibility. There is still a lot of work, engineering work, that needs to be done to make this happen. The incentive is great. It may mean to increase storage density a hundred times decreasing cost at least ten times.

Additionally, this can have an impact on development of quantum computers where again the “noise” is affecting the stability of the computation.

About Roberto Saracco

Roberto Saracco fell in love with technology and its implications long time ago. His background is in math and computer science. Until April 2017 he led the EIT Digital Italian Node and then was head of the Industrial Doctoral School of EIT Digital up to September 2018. Previously, up to December 2011 he was the Director of the Telecom Italia Future Centre in Venice, looking at the interplay of technology evolution, economics and society. At the turn of the century he led a World Bank-Infodev project to stimulate entrepreneurship in Latin America. He is a senior member of IEEE where he leads the New Initiative Committee and co-chairs the Digital Reality Initiative. He is a member of the IEEE in 2050 Ad Hoc Committee. He teaches a Master course on Technology Forecasting and Market impact at the University of Trento. He has published over 100 papers in journals and magazines and 14 books.