Random and ordered arrays of surface magic clusters

Controlling the width of self-assembled dysprosium silicide nanowires on the Si(001) surface

We present STM data that show that it is possible to use a metal induced 2 × 7 reconstruction of Si(001) to narrow the width distribution of Dy silicide nanowires. This behavior is distinct from the effect of the 7 × 7 reconstruction on the Si(111) surface, where the 7 × 7 serves as a static template and the deposited metal avoids the unit cell boundaries on the substrate. In this case, the 2 × 7 is a dynamic template, and the nanowires nucleate at anti-phase boundaries between 2 × 7 reconstruction domains.

Broken even-odd symmetry in self-selection of distances between nanoclusters due to the presence or absence of topological solitons

Depositing particles randomly on a 1D lattice is expected to result in an equal number of particle pairs separated by even or odd lattice units. Unexpectedly, the even-odd symmetry is broken in the self-selection of distances between indium magic-number clusters on a Si(100)-2×1 reconstructed surface. Cluster pairs separated by even units are less abundant because they are linked by silicon atomic chains carrying topological solitons, which induce local strain and create localized electronic states with higher energy. Our findings reveal a unique particle-particle interaction mediated by the presence or absence of topological solitons on alternate lattices.