[en] The nanoscopic magnetic texture forming in a monolayer of iron on the (111) surface of iridium, Fe/Ir(111), is spatially modulated and uniaxially incommensurate with respect to the crystallographic periodicities. As a consequence, a low-energy magnetic excitation is expected that corresponds to the sliding of the texture along the incommensurate direction, i.e., a phason mode, which we explicitly confirm with atomistic spin simulations. Using scanning tunneling microscopy (STM), we succeed to observe this phason mode experimentally. It can be excited by the STM tip, which leads to a random telegraph noise in the tunneling current that we attribute to the presence of two minima in the phason potential due to the presence of disorder in our sample. This provides the prospect of a floating phase in cleaner samples and, potentially, a commensurate-incommensurate transition as a function of external control parameters.
Disciplines :
Physics
Author, co-author :
Yang, Hung-Hsiang; Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, Germany
Desplat, Louise ; Université de Liège - ULiège > Département de physique > Physique des matériaux et nanostructures ; UMR 7054, Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS, Strasbourg, France
Kravchuk, Volodymyr; Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, Karlsruhe, Germany ; Leibniz-Institut für Festkörper-und Werkstoffforschung, IFW Dresden, Dresden, Germany ; Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Hervé, Marie; UMR7588, Institut des NanoSciences de Paris, Sorbonne University and CNRS, Paris, France
Gerber, Simon; Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, Germany
Garst, Markus; Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, Karlsruhe, Germany ; Institute for Quantum Materials and Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany
Dupé, Bertrand ; Université de Liège - ULiège > Département de physique > Physique des matériaux et nanostructures ; Fonds de la Recherche Scientifique (FNRS), Bruxelles, Belgium
Wulfhekel, Wulf; Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe, Germany ; Institute for Quantum Materials and Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany
Chaikin, P. M.; Lubensky, T. C. Principles of Condensed Matter Physics (Cambridge University Press, 1995).
Lyuksyutov, I., Naumovets, A. G. & Pokrovsky, V. Two-Dimensional Crystals (Academic Press, Inc., 1992).
Grüner, G. Density Waves in Solids (CRC Press, 1994).
S. Van Smaalen Incommensurate crystal structures Crystallogr. Rev. 1995 4 79 202 10.1080/08893119508039920
A.W. Overhauser Observability of charge-density waves by neutron diffraction Phys. Rev. B 1971 3 3173 3182 1971PhRvB..3.3173O 10.1103/PhysRevB.3.3173
P. Bak J. von Boehm Ising model with solitons, phasons, and “the devil’s staircase” Phys. Rev. B 1980 21 5297 5308 1980PhRvB.21.5297B 576327 10.1103/PhysRevB.21.5297
G. Grüner The dynamics of charge-density waves Rev. Mod. Phys. 1988 60 1129 1181 1988RvMP..60.1129G 10.1103/RevModPhys.60.1129
P. Brown et al. Strong coupling superconductivity in a quasiperiodic host-guest structure Sci. Adv. 2018 4 eaao4793 2018SciA..4.4793B 10.1126/sciadv.aao4793
H. Ochoa R.M. Fernandes Degradation of phonons in disordered moiré superlattices Phys. Rev. Lett. 2022 128 065901 2022PhRvL.128f5901O 10.1103/PhysRevLett.128.065901
A.D. Bruce R.A. Cowley The theory of structurally incommensurate systems J. Phys. C: Solid State Phys. 1978 11 3609 3630 1978JPhC..11.3609B 10.1088/0022-3719/11/17/014
I. Dzyaloshinsky Theory of helicoidal structures in antiferromagnets Soviet Phys. JETP 1965 20 665 668
K. von Bergmann et al. Observation of a complex nanoscale magnetic structure in a hexagonal Fe monolayer Phys. Rev. Lett. 2006 96 167203 2006PhRvL.96p7203V 10.1103/PhysRevLett.96.167203
S. Heinze et al. Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions Nat. Phys. 2011 7 713 718 10.1038/nphys2045
Meichel, T., Suzanne, J. & Gay, J.-M. 2-dimensional phases adsorbed on a square symmetry substrate - methane and argon on single-crystal MgO (100). C. R. Acad. Sci. Paris 303, 989 (1986).
K. Von Bergmann et al. Tunneling anisotropic magnetoresistance on the atomic scale Phys. Rev. B 2012 86 134422 2012PhRvB.86m4422V 10.1103/PhysRevB.86.134422
L. Desplat B. Dupé Eigenmodes of magnetic skyrmion lattices Phys. Rev. B 2023 107 144415 2023PhRvB.107n4415D 10.1103/PhysRevB.107.144415
K. Von Bergmann A. Kubetzka O. Pietzsch R. Wiesendanger Interface-induced chiral domain walls, spin spirals and skyrmions revealed by spin-polarized scanning tunneling microscopy J. Phys. Condens. Matter. 2014 26 394002 10.1088/0953-8984/26/39/394002
M. Hervé M. Peter W. Wulfhekel High frequency transmission to a junction of a scanning tunneling microscope Appl. Phys. Lett. 2015 107 093101 2015ApPhL.107i3101H 10.1063/1.4929766
T. Balashov et al. Inelastic electron-magnon interaction and spin transfer torque Phys. Rev. B 2008 78 174404 2008PhRvB.78q4404B 10.1103/PhysRevB.78.174404
G. Nunes Jr M.R. Freeman Picosecond resolution in scanning tunneling microscopy Science 1993 262 1029 1032 1993Sci..262.1029N 10.1126/science.262.5136.1029
I. Moult M. Herve Y. Pennec Ultrafast spectroscopy with a scanning tunneling microscope Appl. Phys. Lett. 2011 98 233103 2011ApPhL.98w3103M 10.1063/1.3597351
A.A. Tulapurkar et al. Spin-torque diode effect in magnetic tunnel junctions Nature 2005 438 339 342 2005Natur.438.339T 10.1038/nature04207
M. Hervé M. Peter T. Balashov W. Wulfhekel Towards laterally resolved ferromagnetic resonance with spin-polarized scanning tunneling microscopy Nanomaterials 2019 9 827 10.3390/nano9060827
S. Baumann et al. Electron paramagnetic resonance of individual atoms on a surface Science 2015 350 417 420 2015Sci..350.417B 10.1126/science.aac8703
Buhl, P. M., Desplat, L., Boettcher, M., Meyer, S. Dupe, B. Matjes (Version 1.1.0) [Computer software]. https://doi.org/10.5281/zenodo.12685461 (2024).
G.P. Müller et al. Spirit: multifunctional framework for atomistic spin simulations Phys. Rev. B 2019 99 224414 2019PhRvB.99v4414M 10.1103/PhysRevB.99.224414
P.F. Bessarab V.M. Uzdin H. Jonsson Method for finding mechanism and activation energy of magnetic transitions, applied to skyrmion and antivortex annihilation Comput. Phys. Commun. 2015 196 335 347 2015CoPhC.196.335B 10.1016/j.cpc.2015.07.001
