title: The nature of domain walls in ultrathin ferromagnets revealed by scanning nanomagnetometry.
abstract: The capacity to propagate magnetic domain walls with spin-polarized currents underpins several schemes for information storage and processing using spintronic devices. A key question involves the internal structure of the domain walls, which governs their response to certain current-driven torques such as the spin Hall effect. Here we show that magnetic microscopy based on a single nitrogen-vacancy defect in diamond can provide a direct determination of the internal wall structure in ultrathin ferromagnetic films under ambient conditions. We find pure Bloch walls in Ta/CoFeB(1 nm)/MgO, while left-handed Néel walls are observed in Pt/Co(0.6 nm)/AlOx. The latter indicates the presence of a sizable interfacial Dzyaloshinskii-Moriya interaction, which has strong bearing on the feasibility of exploiting novel chiral states such as skyrmions for information technologies.
authors.affiliation: Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Tetienne
authors.affiliation: Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France.
authors.forename: T
authors.initials: T
authors.lastname: Hingant
authors.affiliation: Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France.
authors.forename: L J
authors.initials: LJ
authors.lastname: Martínez
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS UMR 8502, 91405 Orsay, France.
authors.forename: S
authors.initials: S
authors.lastname: Rohart
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS UMR 8502, 91405 Orsay, France.
authors.forename: A
authors.initials: A
authors.lastname: Thiaville
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, 91405 Orsay, France.
authors.forename: L Herrera
authors.initials: LH
authors.lastname: Diez
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, 91405 Orsay, France.
authors.forename: K
authors.initials: K
authors.lastname: Garcia
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, 91405 Orsay, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Adam
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, 91405 Orsay, France.
authors.forename: J-V
authors.initials: JV
authors.lastname: Kim
authors.affiliation: Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France.
authors.forename: J-F
authors.initials: JF
authors.lastname: Roch
authors.affiliation: INAC-SPINTEC, Université Grenoble Alpes, CNRS, CEA, 38000 Grenoble, France.
authors.forename: I M
authors.initials: IM
authors.lastname: Miron
authors.affiliation: INAC-SPINTEC, Université Grenoble Alpes, CNRS, CEA, 38000 Grenoble, France.
authors.forename: G
authors.initials: G
authors.lastname: Gaudin
authors.affiliation: INAC, CEA and Université Grenoble Alpes, 38054 Grenoble, France.
authors.forename: L
authors.initials: L
authors.lastname: Vila
authors.affiliation: Singulus Technology AG, Hanauer Landstrasse 103, 63796 Kahl am Main, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Ocker
authors.affiliation: Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, 91405 Orsay, France.
authors.forename: D
authors.identifier: 0000000240721457
authors.initials: D
authors.lastname: Ravelosona
authors.affiliation: Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 91405 Orsay, France.
authors.forename: V
authors.initials: V
authors.lastname: Jacques