title: Molecular-scale dynamics of light-induced spin cross-over in a two-dimensional layer.
abstract: Spin cross-over molecules show the unique ability to switch between two spin states when submitted to external stimuli such as temperature, light or voltage. If controlled at the molecular scale, such switches would be of great interest for the development of genuine molecular devices in spintronics, sensing and for nanomechanics. Unfortunately, up to now, little is known on the behaviour of spin cross-over molecules organized in two dimensions and their ability to show cooperative transformation. Here we demonstrate that a combination of scanning tunnelling microscopy measurements and ab initio calculations allows discriminating unambiguously between both states by local vibrational spectroscopy. We also show that a single layer of spin cross-over molecules in contact with a metallic surface displays light-induced collective processes between two ordered mixed spin-state phases with two distinct timescale dynamics. These results open a way to molecular scale control of two-dimensional spin cross-over layers.
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Bairagi
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Univ Paris Sud, Univ Paris Saclay, CNRS, UMR 8182, 91405 Orsay Cedex, France.
authors.forename: Olga
authors.initials: O
authors.lastname: Iasco
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Bellec
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, Univ Paris Saclay, 91191 Gif sur Yvette Cedex, France.|National Research Tomsk State University, 36, Lenina pr., Tomsk 634050, Russia.
authors.forename: Alexey
authors.identifier: 0000-0002-3916-3443
authors.initials: A
authors.lastname: Kartsev
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, Univ Paris Saclay, 91191 Gif sur Yvette Cedex, France.
authors.forename: Dongzhe
authors.identifier: 0000-0003-0929-8125
authors.initials: D
authors.lastname: Li
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lagoute
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Chacon
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Yann
authors.identifier: 0000-0001-5708-4338
authors.initials: Y
authors.lastname: Girard
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rousset
authors.affiliation: CEA/DEN/DANS/DPC/SCCME, Laboratoire d'Etude de la Corrosion Aqueuse, F-91191 Gif-sur-Yvette, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Miserque
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, Univ Paris Saclay, 91191 Gif sur Yvette Cedex, France.
authors.forename: Yannick J
authors.initials: YJ
authors.lastname: Dappe
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, Univ Paris Saclay, 91191 Gif sur Yvette Cedex, France.
authors.forename: Alexander
authors.initials: A
authors.lastname: Smogunov
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, Univ Paris Saclay, 91191 Gif sur Yvette Cedex, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Barreteau
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Univ Paris Sud, Univ Paris Saclay, CNRS, UMR 8182, 91405 Orsay Cedex, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Boillot
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux d'Orsay, Univ Paris Sud, Univ Paris Saclay, CNRS, UMR 8182, 91405 Orsay Cedex, France.
authors.forename: Talal
authors.identifier: 0000-0002-9311-3463
authors.initials: T
authors.lastname: Mallah
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Univ Paris Diderot, Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Repain