mats persson (1) , hyo-june lee (2) , and wilson ho (2)
DESCRIPTION
Exchange splitting in electronic states of single atoms and magnetic coupling in single dimers and trimers on a surface. Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2) ( 1) Dept. of Applied Physics, Chalmers/Göteborg University, SWEDEN - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/1.jpg)
Exchange splitting in electronic states of single atoms and magnetic coupling in single dimers and trimers on a surface
Mats Persson(1), Hyo-June Lee(2), and Wilson Ho(2)
(1)Dept. of Applied Physics, Chalmers/Göteborg University, SWEDEN
(2)Dept. of Physics and Astronomy and Dept. of Chemistry , University of California, Irvine, USA
![Page 2: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/2.jpg)
Outline
• Non-magnetic Au atom and dimer on NiAl(110) surface
• Magnetic Co, Fe, Mn atoms and dimers, and Fe trimer on NiAl(110) surface
Tunneling spectra with a non-magnetic tip and density functional calculations of:
______________________________________________________________________N. Nilius, T. M. Wallis, M. Persson, and W. Ho., Phys. Rev. Lett. 90, 196103 (2003)H. J. Lee, W. Ho, and M. Persson, Phys. Rev. Lett. 92, 186802 (2004)
![Page 3: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/3.jpg)
Non-magnetic Au atom and dimers on a NiAl(110) surface
• STS of Au adatom and ad-dimers.• Density functional calculation (PAW-GGA)
VASP
![Page 4: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/4.jpg)
Au Adatom and Ad-dimers*
* Nilius, Wallis, Persson, and Ho, Phys. Rev. Lett. 90, 196103 (2003)
![Page 5: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/5.jpg)
Tunneling Spectra and Images of an Au Ad-dimer
![Page 6: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/6.jpg)
Density Functional Calculations: Au Adatom and Ad-dimers
PW-PAW-GGA (VASP)
Adatom Ad-dimer
![Page 7: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/7.jpg)
Au Adatom
![Page 8: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/8.jpg)
Au Ad-dimer
![Page 9: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/9.jpg)
Resonance Energy Splittings of Dimers
![Page 10: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/10.jpg)
Magnetic atoms, dimers and trimer on a NiAl(110) surface*
• STS of Co, Fe, and Mn adatoms and ad-dimers and Fe ad-trimer
• Density functional calculation (PAW-GGA) VASP
___________________________________________________________*H. J. Lee, W. Ho, and M. Persson, Phys. Rev. Lett. 92, 186802 (2004)
![Page 11: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/11.jpg)
Magnetic adatoms at 17 K
![Page 12: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/12.jpg)
Calculated Magnetic Adatom DOS
![Page 13: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/13.jpg)
![Page 14: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/14.jpg)
Two Level System with a Spin
Ferromagnetic Anti FerromagneticNon-magnetic
![Page 15: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/15.jpg)
Magnetic Co and Fe Addimers: LDOS
Co2/NiAl(110)
E0(AFM)-E0(FM) = 0.42eV
Strong adatom-adatom interaction Interadatom distance (d = 2.2 Å) shorter than bridge-bridge distance (2.9 Å)
Fe2/NiAl(110)
E0(AFM)-E0(FM) = 0.45eV
![Page 16: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/16.jpg)
Magnetic Mn Addimer: LDOS
E0(AFM)-E0(FM) = 0.036eV
Weak adatom-adatom interaction Interadatom distance (d = 3.0 Å) close to the bridge-bridge distance (2.9 Å)
![Page 17: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/17.jpg)
![Page 18: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/18.jpg)
Magnetic Fe Ad-trimer
![Page 19: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/19.jpg)
Concluding Remarks
• Unoccupied Kohn-Sham states give a useful approximation and physical insights of tunneling spectra of resonances in atom nanostructures on NiAl(110)
• Non-Kondo resonance signatures of the spin state in magnetic adatoms, ad-dimers and ad-trimer
![Page 20: Mats Persson (1) , Hyo-June Lee (2) , and Wilson Ho (2)](https://reader036.vdocument.in/reader036/viewer/2022062305/56814904550346895db63b5d/html5/thumbnails/20.jpg)
AcknowledgementsExperiments:Niklas Nilius and Mitch Wallis, UC Irvine, USA
Theory:Doug Mills and Ruqian Wu, UC Irvine, USA
R. Bechara Muniz, Univ. Federal Fluminense, Niteroi, Brazil
Funding: