André Kubetzka

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Topologically nontrivial spin textures have recently been investigated for spintronic applications. Here, we report on an ultrathin magnetic film in which individual skyrmions can be written and deleted in a controlled fashion with local spin-polarized currents from a scanning tunneling microscope. An external magnetic field is used to tune the energy(More)
Chirality is a fascinating phenomenon that can manifest itself in subtle ways, for example in biochemistry (in the observed single-handedness of biomolecules) and in particle physics (in the charge-parity violation of electroweak interactions). In condensed matter, magnetic materials can also display single-handed, or homochiral, spin structures. This may(More)
Single magnetic atoms on surfaces are the smallest conceivable units for two-dimensional magnetic data storage. Previous experiments on such systems have investigated magnetization curves, the many-body Kondo effect and magnetic excitations in quantum spin systems, but a stable magnetization has not yet been detected for an atom on a non-magnetic surface in(More)
The atomic-scale spin structure of individual isolated Skyrmions in an ultrathin film is investigated in real space by spin-polarized scanning tunneling microscopy. Their axial symmetry as well as their unique rotational sense is revealed by using both out-of-plane and in-plane sensitive tips. The size and shape of Skyrmions change as a function of the(More)
Fe nanostripes on W(110) are investigated by Kerr magnetometry and spin-polarized scanning tunneling microscopy (SP-STM). An Arrhenius law is observed for the temperature dependent magnetic susceptibility indicating a one-dimensional magnetic behavior. The activation energy for creating antiparallel spin blocks indicates extremely narrow domain walls with a(More)
The search for uncompensated magnetic moments on antiferromagnetic surfaces is of great technological importance as they are responsible for the exchange-bias effect that is widely used in state-of-the-art magnetic storage devices. We have studied the atomic spin structure of phase domain walls in the antiferromagnetic Fe monolayer on W(001) by means of(More)
Spin-averaged and spin-polarized scanning tunneling spectroscopy at low temperature was performed on nanometer-scale triangular Co islands grown epitaxially on Cu(111) in the submonolayer coverage regime. Two structurally different island types can clearly be distinguished by their spin-averaged electronic structure. Spin-polarized measurements allow a(More)
Scanning tunneling spectroscopy (STS) of thin Fe films on W(110) shows that the electronic structure of domains and domain walls is different. This experimental result is explained on the basis of first-principles calculations. A detailed analysis reveals that the spin-orbit induced mixing between minority d(xy+xz) and minority d(z(2)) spin states depends(More)
Vector spin chirality is one of the fundamental characteristics of complex magnets. For a one-dimensional spin-spiral state it can be interpreted as the handedness, or rotational sense of the spiral. Here, using spin-polarized scanning tunneling microscopy, we demonstrate the occurrence of an atomic-scale spin spiral in finite individual bi-atomic Fe chains(More)
Using spin-polarized scanning tunneling spectroscopy, we reveal how the standing wave patterns of confined surface state electrons on top of nanometer-scale ferromagnetic Co islands on Cu(111) are affected by the spin character of the responsible state, thus experimentally confirming a very recent theoretical result. Furthermore, at the rim of the islands a(More)