Berlin 2005 – wissenschaftliches Programm

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MA: Magnetismus

MA 18: Magnetische dünne Schichten III

MA 18.6: Vortrag

Montag, 7. März 2005, 11:45–12:00, TU H1028

Displacement Profile of Domain Walls at Critical Depinning — •Thomas Nattermann and Andreas Glatz — Institut für Theoretische Physik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln

The influence of a strong surface potential on the critical depinning of an elastic system driven in a random medium is considered. If the surface potential prevents depinning completely the elastic system shows a parabolic displacement profile. Its curvature C exhibits at zero temperature a pronounced rhombic hysteresis curve of width 2f_c with the bulk depinning threshold f_c. The hysteresis disappears at non-zero temperatures if the driving force is changed adiabatically. If the surface depins by the applied force or thermal creep, C is reduced with increasing velocity. The results apply, e.g., to driven magnetic domain walls, flux-line lattices and charge-density waves