1 / 21

Weighting a Domain Wall

Weighting a Domain Wall. Journal Club February 15 2005 Current-Induced resonance and mass determination of a single magnetic domain wall, Nature 432 , 203 (2004) Elji Saitoh, Hideki Miyajima, Takehiro Yamaoka and Gen Tatara. Motivation.

mickey
Download Presentation

Weighting a Domain Wall

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Weighting a Domain Wall Journal Club February 15 2005 Current-Induced resonance and mass determination of a single magnetic domain wall, Nature 432, 203 (2004) Elji Saitoh, Hideki Miyajima, Takehiro Yamaoka and Gen Tatara

  2. Motivation • Fundammental Phyics: interaction between currents and Domain Walls • Great Experiment • Opens INTERESTING QUESTIONS (Related to our future work) • Related to some of my recent work: • JFR, M. Braun, A.S. Núñez, AH. MacDonald Phys. Rev. B 2004 • J. J. Palacios, D. Jacob, JFR, cond-mat/2004 • L. Brey, C. Tejedor, JFR, APL 2004

  3. What is a Domain Wall (DW) Ferromagnetic Ground State. Good for local EXCHANGE. BAD for Magnetostatics Ferromagnetic DOMAIN EXCHANGE ok except in the WALL GOOD for Magnetostatics DOMAIN and GROUND STATE ARETOPOLOGICALLY DIFFERENT DOMAIN WALL

  4. Thin DW DW: Thick or Thin COMPETION between EXCHANGE and anisotropic interactions Exchange favors thick DW Anis. Int. Favors thin DW Thick DW

  5. Domain Wall Motion

  6. Domain Wall Motion

  7. Domain Wall Motion

  8. The Experiment

  9. Justification of x y Clockwise  Anti- Clockwise

  10. LATER: • Why a DW can be considered a particle with mass? • What is a “magnetic charge”?

  11. MagneticForceMicroscopy Resistance vs a.c. frequency

  12. Resistance vs a.c. frequency

  13. mDW=(6.55+- 0.06 ) 10-23 Kg                                                                          , Is: spin current f: frequency m: DW mass, : DW relaxation time n: conduction electron density RDW: DW resistance I: total current

  14. DW: From Field to Particle M,x, F(x) • PAPERS: • S. Takagi and G. Tatara, Phys. Rev. B 54, 9920 (1996). • H-B. Braun and D. Loss, Phys. Rev. B 53, 3237 (1996); • P. C. E. Stamp, Phys. Rev. Lett. 66, 2802 (1991). • E. M. Chudnovsky, O. Iglesias, and P. C. E. Stamp, Phys. Rev. B 46, 5392 (1992). .

  15. DW: From Field to Particle Classical Lagrangian of a Field

  16. DW “mass” “Magnetic Charge” Magnetic Energy

  17. Magnetostatics “Magnetic Charge” Polarization Charge

  18. DW theory EXCHANGE

More Related