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2017-10-17

Public evening talk in Hamburg

On the occasion of the "Nacht des Wissens" (public night of science), I will give an overview oral presentation about what you can learn from analyzing the telegraphic noise recorded on superparamagnetic nanomagnets:

Telegramme aus der Nanowelt: Was die Atome uns erzählen (in German) Details

Sat, 2017-11-04, 21:00-21:45, Department of Physics, Lecture Hall INF, Jungiusstrasse 11A, Hamburg

More detailed information on the "Nacht des Wissens", including the full propramme of all contributing scientific institutions in Hamburg, can be found here:
nachtdeswissens.hamburg.de

2016-10-27

Meet me in New Orleans

You are attending the 61st Annual Conference on Magnetism and Magnetic Materials (MMM)? Please feel free to join my presentation, focussing on our most recent research:

Thu, 2016-11-03, 8:54-9:06, EC-03, Room La Galeries 1-2
High Frequency Magnetization Dynamics of Individual Atomic-Scale Magnets
S. Krause, A. Sonntag, J. Hermenau, J. Friedlein, and R. Wiesendanger

2016-08-07

Meet me at the upcoming conferences in Asia

You are attending the International Conference on Nanoscience and Technology (ICN+T) in Busan (South Korea)? Or the SPSTM-6 in Chiba (Japan)? Please feel free to join one of my presentations, focussing on our most recent research:

ICN+T: Tue, 2016-08-23, 12:15-12:30, NS-05-2-O-TU (oral presentation), Room 102
High Frequency Magnetization Dynamics of Individual Atomic-Scale Magnets
S. Krause, A. Sonntag, J. Hermenau, J. Friedlein, and R. Wiesendanger

ICN+T: Tue, 2016-08-23, 14:45-15:00, NS-06-3-O-TU (oral presentation), Room 102
A Magnetic Nano-Skyrmion Lattice Observed in a Si-Wafer Based Multilayer System
A. Schlenhoff, P. Lindner, J. Friedlein, S. Krause, R. Wiesendanger, M. Weinl, M. Schreck, and M. Albrecht

SPSTM-6: Tue, 2016-08-30, 9:20-10:00 (Invited Talk)
High Frequency Magnetization Dynamics of Individual Atomic-Scale Magnets
S. Krause

2015-11-04

Public evening talk in Hamburg

On the occasion of the "Nacht des Wissens" (public night of science), I will give an overview oral presentation about what you can learn from analyzing the telegraphic noise recorded on superparamagnetic nanomagnets:

Telegramme aus der Nanowelt: Was die Atome uns erzählen (in German)

Sat, 2015-11-07, 22:00-22:30, Department of Physics, Lecture Hall INF, Jungiusstrasse 11A, Hamburg

More detailed information on the "Nacht des Wissens", including the full propramme of all contributing scientific institutions in Hamburg, can be found here:
nachtdeswissens.hamburg.de

2015-09-15

Public talk in Hamburg

On the occasion of the re-opening of the nano-exhibtion "Nanotechnologie: Aufbruch in neue Welten", I will give a public talk at the Physics Institutes on the campus Jungiusstraße in Hamburg:

Telegramme aus der Nanowelt: Magnetisierungsdynamik auf atomarer Skala (in German)

Fri, 2015-09-18, 15:00-15:30 + Sat, 2015-09-19, 15:00-15:30

More detailed information on the re-opening event can be found here:
www.nanotechnologie-ausstellung.de

2015-07-02

Meet me at the ICM in Barcelona

If you plan to attend the International Conference on Magnetism (ICM-20) in Barcelona, please feel free to join one of my presentations, focussing on our most recent research:

Wed, 2015-07-08, 12:00-12:15, WE.G2_O2 (oral presentation), Room B1-B3
Electric-Field-Induced Magnetic Anisotropy in a Nanomagnet Investigated on the Atomic Scale
J. P. Hermenau, A. Sonntag, A. Schlenhoff, J. Friedlein, S. Krause, and R. Wiesendanger

Fri, 2015-07-10, 14:30-16:00, FR.H-P08 (poster presentation), Exhibition Hall
Thermal Stability of an Interface-Stabilized Skyrmion Lattice
S. Krause, A. Sonntag, J. Hermenau, and R. Wiesendanger

Fri, 2015-07-10, 17:15-17:30, FR.I.3_O1 (oral presentation), Room D4-D6
A Magnetic Nano-Skyrmion Lattice Observed in a Si-Wafer Based Multilayer System
S. Krause, A. Schlenhoff, P. Lindner, J. Friedlein, R. Wiesendanger, M. Weinl, M. Schreck, and M. Albrecht

2015-05-12

New paper in ACS Nano

Magnetic Nano-skyrmion Lattice Observed in a Si-Wafer-Based Multilayer System

Growth, electronic properties, and magnetic properties of an Fe monolayer (ML) on an Ir/YSZ/Si(111) multilayer system have been studied using spin-polarized scanning tunneling microscopy. Our experiments reveal a magnetic nano-skyrmion lattice, which is fully equivalent to the magnetic ground state that has previously been observed for the Fe ML on Ir(111) bulk single crystals. In addition, the experiments indicate that the interface-stabilized skyrmion lattice is robust against local atomic lattice distortions induced by multilayer preparation.

A. Schlenhoff, P. Lindner, J. Friedlein, S. Krause, R. Wiesendanger, M. Weinl, M. Schreck, and M. Albrecht

ACS Nano 9, 5908 (2015) DOI
2014-08-13

New paper in Physical Review Letters

Thermal Stability of an Interface-Stabilized Skyrmion Lattice

The thermal stability of the magnetic nano-skyrmion lattice in the monolayer Fe/Ir(111) is investigated using temperature dependent spin-polarized scanning tunneling microscopy. Our experiments show that the skyrmion lattice disappears at a temperature of Tc=27.8 K, indicating a loss of long-range magnetic order. At second-layer iron islands the lattice is pinned and local order persists at temperatures above Tc. The findings are explained in terms of the complex magnetic interactions involved in the formation of the skyrmion lattice.

A. Sonntag, J. Hermenau, S. Krause, and R. Wiesendanger

Phys. Rev. Lett. 113, 077202 (2014) DOI
2014-01-08

New paper in Physical Review Letters

Electric-Field-Induced Magnetic Anisotropy in a Nanomagnet Investigated on the Atomic Scale

Magnetoelectric coupling is studied using the electric field between the tip of a spin-polarized scanning tunneling microscope and a nanomagnet. Our experiments show that a negative (positive) electric field stabilizes (destabilizes) in-plane magnetization against thermal agitation, whereas it destabilizes (stabilizes) out-of-plane magnetization. We conclude that the electric field E induces a uniaxial anisotropy that favors in-plane magnetization for E<0 and out-of-plane magnetization for E>0. Our experiments demonstrate magnetic manipulation on the atomic scale without exploiting spin or charge currents.

A. Sonntag, J. Hermenau, A. Schlenhoff, J. Friedlein, S. Krause, and R. Wiesendanger

Phys. Rev. Lett. 112, 017204 (2014) DOI
2013-11-01

Invited talk at the MMM conference in Denver, CO (USA)

I am happy to announce that I will present an invited talk at the upcoming MMM conference in Denver, Colorado. The title will be "Current-Driven Spin Dynamics of Artificially Constructed Quantum Magnets", and I will summarize the main results from our recent Science paper.

Download conference program

2013-01-04

New paper in Science magazine

Current-Driven Spin Dynamics of Artificially Constructed Quantum Magnets

As illustrated in the present volume of the magazine Science, we have constructed, atom-by-atom, the world’s smallest stable ferromagnet composed of only five iron atoms. These magnets can be utilized in future magnetic storage technology based on atomic spin elements using their special quantum properties.

The work clearly demonstrates how the different magnetic interactions can be controlled to design stable magnets which can be switched electrically. Moreover, this research, with its ultimate combination of spatial, magnetic, and temporal resolution of individual magnetic atoms, opens up the future for the ultimate miniaturization of spin-based technology down to the atomic scale.

Links:
Press release (from www.sfb668.de)
Original article in Science

A. A. Khajetoorians, B. Baxevanis, C. Hübner, T. Schlenk, S. Krause, T. O. Wehling, S. Lounis, A. Lichtenstein, D. Pfannkuche, J. Wiebe, and R. Wiesendanger
Science 339, 55 (2013) DOI

2012-08-28

New paper in Physical Review Letters

Individual Atomic-Scale Magnets Interacting with Spin-Polarized Field-Emitted Electrons

We resonantly inject spin-polarized field-emitted electrons in thermally switching nanomagnets. A detailed lifetime analysis as a function of the spin-polarized emission current reveals that considerable Joule heating is generated, and spin-transfer torque results in a directed switching. A trend of higher switching efficiency per electron is observed with an increasing emission current, probably due to the excitation of Stoner modes. On a quasistable nanomagnet, a spin-polarized emission current in the low nA regime already triggers magnetization reversal, thereby demonstrating the high impact of hot-electron spins onto atomic-scale magnets.

A. Schlenhoff, S. Krause, A., and Roland Wiesendanger:
Phys. Rev. Lett. 109,097602 (2012) DOI