DPG Phi
Verhandlungen
Verhandlungen
DPG

Regensburg 2004 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

TT: Tiefe Temperaturen

TT 31: Supraleitung: Vortexdynamik, Vortexphasen, Pinning

TT 31.2: Talk

Friday, March 12, 2004, 10:30–10:45, H20

Study of semifluxons in artificial long Josephson 0-π-junctions — •Tobias Gaber1, Edward Goldobin1,2, Albert Sterck1, Dieter Koelle1, and Reinhold Kleiner11Physikalisches Institut, Experimentalphysik II, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen — 2Institut für Mikro- und Nanoelektronische Systeme, Universität Karlsruhe (TH), Hertzstr. 16, D-76187 Karlsruhe

In long Josephson junctions (LJJ) consisting of two parts with positive and negative critical current (0 and π parts) half-integer vortices (semifluxons) can spontaneously appear at the boundary between these parts.
Such a boundary formally corresponds to a π-discontinuity of the Josephson phase. In our experiments we artificially create such a discontinuity in conventional Nb-AlOx-Nb LJJs using a pair of current injectors. Such JJs allow one to study arbitrary fractional vortices and their dynamics.
In the 0-π-state the Ic(H) dependence shows a minimum at H = 0 as in natural 0-π-LJJs. We investigate the dynamics of the magnetic flux in such junctions for various lengths and observe half-integer zero-field steps (ZFS) with n= 1/2,3/2,5/2 on the IV-characteristics which appear due to the motion of semi-integer flux. We also show that semi-integer ZFS quantisation persists even when arbitrary fractional vortices (other that Φ0/2) are participating in the motion.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2004 > Regensburg