title: Kondo effect in a neutral and stable all organic radical single molecule break junction.
abstract: Organic radicals are neutral, purely organic molecules exhibiting an intrinsic magnetic moment due to the presence of an unpaired electron in the molecule in its ground state. This property, added to the low spin-orbit coupling and weak hyperfine interactions, make neutral organic radicals good candidates for molecular spintronics insofar as the radical character is stable in solid state electronic devices. Here we show that the paramagnetism of the polychlorotriphenylmethyl radical molecule in the form of a Kondo anomaly is preserved in two- and three-terminal solid-state devices, regardless of mechanical and electrostatic changes. Indeed, our results demonstrate that the Kondo anomaly is robust under electrodes displacement and changes of the electrostatic environment, pointing to a localized orbital in the radical as the source of magnetism. Strong support to this picture is provided by density functional calculations and measurements of the corresponding nonradical species. These results pave the way toward the use of all-organic neutral radical molecules in spintronics devices and open the door to further investigations into Kondo physics.
authors.affiliation: †Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Frisenda
authors.affiliation: †Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
authors.forename: Rocco
authors.initials: R
authors.lastname: Gaudenzi
authors.affiliation: ‡Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Franco
authors.affiliation: ‡Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Mas-Torrent
authors.affiliation: ‡Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Concepció
authors.initials: C
authors.lastname: Rovira
authors.affiliation: ‡Institut de Ciéncia de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
authors.affiliation: §Departament de Química Física and Institut de Química Teórica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain.
authors.forename: Isaac
authors.initials: I
authors.lastname: Alcon
authors.affiliation: §Departament de Química Física and Institut de Química Teórica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain.|∥Institició Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Bromley
authors.affiliation: †Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
authors.forename: Enrique
authors.initials: E
authors.lastname: Burzurí
authors.affiliation: †Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
authors.forename: Herre S J
authors.initials: HS
authors.lastname: van der Zant
keywords: Kondo effect; Single molecule; break junction; electrical transport; magnetism; organic radical