Giant spin signals in chemically functionalized multiwall carbon nanotubes


Faced with the technological and societal challenges represented by the storage, transfer and processing of computer data, electronic devices exploit- ing the quantum nature of electrons have been integrated for many years in the computers, smartphones and other daily-used electronic circuits. Prob- lem: the quantum information carried by these electrons that could make these computers even more powerful if fully used is still very unstable in nature. It is practically impossible to transport it without losing it between the components present on electronic boards. In order to overcome this instability and to gain considerably in data processing speed, the Laboratory of Materials and Quantum Phenomena at the Université de Paris and the Institute of Condensed Matter and Nanosciences of the Université catholique de Louvain have managed to create an artificial nanostructure allowing the transport over long distances of quantum information using spintronics, a technology which consists in using the spin of each electron in addition to their charge.

In this research, this crucial step of transportation to overcome the volatile nature of the spin is based on a beneficial combination of different phenomena. First, a strongly spin-polarized charge current is injected using highly spin-polarized hybridized states emerging at the complex ferromagnetic metal/molecule interfaces. Second, the spin information is brought toward the conducting inner shells of a multi-wall carbon nanotube used as a confined nanoguide benefiting from both weak spin-orbit and hyperfine interactions. The spin information is finally electrically converted because of a strong magnetoresistive effect. The experimental results are also supported by calculations qualitatively revealing exceptional spin transport properties of this system.

Référence : R. Bonnet, P. Martin, S. Suffit, P. Lafarge, A. Lherbier, J.-C. Charlier, M.-L. Della Rocca, C. Barraud, Science Advances 6, eaba5494 (31 July 2020).

Published on August 17, 2020