Self-organized defect strings in two-dimensional crystals.
Using experiments with single-particle resolution and computer simulations we study the collective behavior of multiple vacancies injected into two-dimensional crystals. We find that the defects assemble into linear strings, terminated by dislocations with antiparallel Burgers vectors. We show that these defect strings propagate through the crystal in a succession of rapid one-dimensional gliding and rare rotations. While the rotation rate decreases exponentially with the number of defects in the string, the diffusion constant is constant for large strings. By monitoring the separation of the dislocations at the end points, we measure their effective interactions with high precision beyond their spontaneous formation and annihilation, and we explain the double-well form of the dislocation interaction in terms of continuum elasticity theory.
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, 6020 Innsbruck, Austria and Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria.
Wolfgang
W
Lechner
Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
David
D
Polster
Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
Georg
G
Maret
Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
Peter
P
Keim
Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
Christoph
C
Dellago