Quantum World at Atomic Scale: Spin-Polarized Scanning ...spin/course/109F/Lecture13 STM...2017/12/09 [email protected] 3 Scanning Tunneling Microscopy Background The Nobel

Quantum World at Atomic Scale:

Spin-Polarized Scanning Tunneling Microscopy

1. Institute of Applied Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany

2. Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan

Pin-Jui Hsu1,2 (徐斌睿)

2017/12/09 [email protected] 1

H/ Fe-DL/ Ir(111)Fe-DL/ Rh(001) Fe-TL/ Ir(111)

2017/12/09 [email protected] 2

Outline

➢ Research Motivation

⚫ To image, detect, and manipulate low-dimensional systems by SP-STM with spin resolution.

➢ Introductions & Literatures

⚫ What SP-STM can do ?

◆ Atomic Spin Lattice : Non-collinear Magnetism

➢ Chiral Domain Wall, Spin Spiral, Magnetic Skyrmions

◆ SP-STS : LDOS, QPI, IETS, Image State, Landau Splitting, QPC

➢ Kondo Resonance, Band Dispersion, Phonon Excitation

◆ Atom Manipulation : Zeeman Splitting, Magnetic Hysteresis

➢ Magnetic Moment, Magnetocrystalliine Anisotropy, RKKY Coupling Strength

◆ Time Resolution : Pump-Probe Dynamics, Atomic Dipolar Fields

➢ Electron Spin Resonance, Dipole-dipole Interaction

➢ Summary & Future Highlights

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Scanning Tunneling MicroscopyBackground

The Nobel Prize in Physics 1986 ~

"for his fundamental work in electron optics, and for the design of the first electron microscope"

"for their design of the scanning tunneling microscope"

”See” the atomic scale world !!

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Scanning Tunneling MicroscopyWorking Principle

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Scanning Tunneling MicroscopyOperation Modes

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Scanning Tunneling MicroscopyWorking Principle

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Scanning Tunneling MicroscopyVarious Systems

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Experimental InstrumentsVarious types of STM in Hamburg

➢ Home built 4K-STM with 3D Magnets ➢ Home built 300 mK-STM with 12T Magnet

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Experimental InstrumentsVarious types of STM in Hamburg

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Experimental InstrumentsVarious types of STM in Hamburg

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Scanning Tunneling MicroscopyScanner Piezo Tube

Tube Scanners

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Scanning Tunneling MicroscopyScanner Piezo Tube

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Scanning Tunneling MicroscopyScanner Piezo Tube

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Scanning Tunneling MicroscopyScanner Piezo Tube

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Scanning Tunneling MicroscopyScanner Piezo Tube

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Scanning Tunneling MicroscopyCoarse Piezo Motor

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Scanning Tunneling MicroscopyCoarse Piezo Motor

ΔZfine ≥ ΔZcoarse

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Scanning Tunneling SpectroscopyWorking Principle

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Scanning Tunneling SpectroscopyWorking Principle

E-EF (meV)d

I/d

U(a

. u.)

➢ MnPc → Kondo resonance.

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Scanning Tunneling SpectroscopyWorking Principle

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Scanning Tunneling SpectroscopyWorking Principle

Quantum World at Atomic Scale:

Spin-Polarized Scanning Tunneling Microscopy

1. Institute of Applied Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany

2. Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan

Pin-Jui Hsu1,2 (徐斌睿)

2017/12/09 [email protected] 22

H/ Fe-DL/ Ir(111)Fe-DL/ Rh(001) Fe-TL/ Ir(111)

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Spin-Polarized STMWorking Principle

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Spin-Polarized STMWorking Principle

Mn/ W(110)

Topo. Cr(001)dI/dU

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Spin-Polarized STMMagnetic Domain Wall

Bloch Wall

Neél Wall

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Spin-Polarized STMMagnetic Domain Wall, AFM Cr(001)

Cr(001)

R. Wiesendanger, Rev. Mod. Phys., 81, 1495 (2009)

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Spin-Polarized STMMagnetic Domain Wall, FM Fe-DL/W(110)

R. Wiesendanger, Rev. Mod. Phys., 81, 1495 (2009)

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Spin-Polarized STMMagnetic Domain Wall, FM Fe-DL/W(110)

O. Pietzsch et al., Science, 292, 2053 (2001)

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Spin-polarized StatesSpin-polarized Surface State, FM Co-DL/Cu(111)

O. Pietzsch et al., Phys. Rev. Lett., 92, 057202 (2004)

L. Diekhöner et al., Phys. Rev. Lett., 90, 236801 (2003)

H. Oka et al., Science, 327, 843 (2010)

Topography Z(x,y) Conduc. dI/dU(x,y)

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Spin-Polarized STMAtomic Spin Resolution, AFM Fe-ML/W(001)

A. Kubetzka et al., Phys. Rev. Lett., 90, 236801 (2003)

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Spin-Polarized STMAtomic Spin Resolution, AFM Mn-ML/W(110)

M. Bode et al., Nature, 447, 190 (2007)

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Magnetic SkyrmionDzyaloshinsky-Moriya Interaction

➢ DMI has the dominant contributions to

formation of magnetic skyrmion spin texture.

A, Fert, V. Cros, and J. Sampaio, Nature Nano., 8, 152 (2013)

➢ The current density required to move skyrmions has 5~6 order of magnitudes

smaller than DW movement.

➢ Non-trivial topology and lower depinningcurrents lead to low energy consumption.

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Spin-Polarized STMMagnetic Phase transition, Magnetic Skyrmions

N. Romming et al., Science, 341, 636 (2013)

P. J. Hsu et al., Nat. Nano., 12, 123 (2017)

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J, Barker, and O. A. Tretiakov, Phys. Rev. Lett.,116, 147203 (2016)

A. K. Nayak, V. Kumar, P. Werner, E. Pippel, R. Sahoo, F. Damay, U. K.Roßler, C. Felser, and S. P. Parkin, Nature, 548, 561 (2017)

B. Dupé, C. N. Kruse, T. Dornheim, and S. Heinze, New. J. Phys., 18,055015 (2016)

Magnetic SkyrmionAFM skyrmion; Antiskyrmion; |Q| > 1

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Single-Atom MagnetometrySP-STM/STS with B field, Co atoms/Pt(111)

F. Meier et al., Science, 320, 82 (2008)

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Single-Atom MagnetometryMoving Single Atoms

M. F. Crommie et al., Science, 262, 218 (1993)

75 Fe/ Cu(111)

34 Xe / Ni(110)

CO/ Cu(111)

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Single-Atom MagnetometryMoving Single Atoms, Lateral Movement

S. W. Hla, J. Vac. Sci. & Tech. B, 23, 1351 (2005)

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Single-Atom MagnetometryMoving Single Atoms, Vertical Manipulation

K. K. Gomes et al., Nature, 483, 306 (2012)

271 CO/ Cu(111)

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Moving Single AtomsSpin Logic Operations

A. Khajetoorians et al., Science, 332, 1062 (2011)

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SP-STM with Time ResolutionSingle-Atom Dynamics

S. Baumann et al., Science, 417, 350 (2015)

T. Choi et al., Nat. Nanotech., 12, 420 (2017)

F. D. Natterer et al., Nature, 543, 226 (2017)

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Summary & Future HighlightsThere are more to explore !!

Thanks for your attention !