Disruptive phononics-based approach to information technology: the ERC AdG “LEIT” project kicks off today

by Virginia Greco

A scientific kick-off meeting marks today the starting of the LEIT (Lossless information for emerging information technologies) project, which will be led by ICREA Prof. Dr Clivia M. Sotomayor Torres, head of the ICN2 Phononic and Photonic Nanostructures Group. In 2020, Prof. Sotomayor was awarded an ERC Advanced Grant for this five-year project, which aims at developing a disruptive technology based on phononic interconnects to reduce energy consumption of electronic circuits.

The fast increase of energy consumption and waste, due to the progressive development and penetration in our daily life of information technology and the internet of things, has become a very pressing problem, which requires a radical change in the electronic and communication technologies that we use. Nanoelectronics has enabled further miniaturization and integration providing ever-increasing processing capacity, but new issues have emerged or become more relevant, such as increased heating problems. Another critical point is that interconnects – the connections between various elements of a circuit – use more energy than microprocessors themselves.

ICREA Prof. Dr Clivia Sotomayor Torres, leader of the ICN2 Phononic and Photonic Nanostructures Group, has proposed an innovative approach to address the interconnect energy-consumption challenge. Her five-year project LEIT, from “Lossless information for emerging information technologies”, will develop structures that allow taking advantage of phonon properties to transmit information using small amounts of energy.

Awarded with a European Research Council Advanced Grant, the LEIT project will officially meet today – January 29, 2021 – with a scientific online kick-off meeting. Besides Prof. Sotomayor’s group, the partner team from the VTT Technical Research Centre of Finland Ltd., and collaborators from the University of Science and Technology of Lille (France) and from CEA, Grenoble (France) will participate in the event.

Phonons as low-energy consumption information carriers

Phonons, which are quanta of lattice vibration, can be used as information carriers and their transmission requires only a fraction of a millielectronVolt (meV) of energy, which is very low compared to present systems using electrons and/or light as carriers. The drawback of this approach is that phonons suffer phonon-phonon scattering and losses in waveguides caused by interaction with lattice defects and other complex phenomena.

In the LEIT project, Prof. Sotomayor and her group will design novel crystal structures that, thanks to a unique combination of features, will permit phonon filtering, reflection and confinement, as well as transmission from one element to another. These phononic topological waveguides will be aimed at reducing losses and ensuring a longer phonon lifetime to transmit signals. The structures will be made from silicon (Si) and Si-compatible materials, also incorporating transition metal dichalcogenides, thus they can be easily integrated in current electronic circuitry.

Drawing on their extensive experimental research on phonons in semiconductor nanostructures, Si membranes and phononic crystals, Prof. Sotomayor’s team aims at demonstrating the viability of acoustic phonons as low-energy information carriers. This would lay the scientific and technological foundations of a new phononics-based approach to information processing, with crucial advantages in terms of low energy-consumption, reliability and compactness.

The LEIT project has been awarded a European Research Council (ERC) Advanced Grant (under the European Union's Horizon 2020 Research and Innovation Programme, grant agreement No 885689) for its innovative potential and the solid background of Prof. Sotomayor on the topic. It is a prestigious grant established by the European Union to fund ground-breaking, high-risk projects proposed by outstanding research leaders, who have an exceptional track-record of significant research achievements in the 10 years previous to application.