Further indications of Tomonaga-Luttinger liquid behavior in the complex Au/Ge(001) surface structure

Several studies on Au-induced nanowires on Ge(001) have provided results that have led to contradictory interpretations concerning the dimensionality of the electronic structure and the existence of a Tomonaga-Luttinger liquid. In this work, we present local density-of-states maps that reveal a distinctly striped electronic structure. These stripes run in a slight zigzag course that is oriented almost orthogonally to the nanowires, which are visible in scanning tunneling microscopy images. Power law exponents extracted from a large number of different measurements agree with predictions for a Tomonaga-Luttinger liquid. Furthermore, exponents obtained from channel ends are significantly enhanced, an additional hallmark of a Tomonaga-Luttinger liquid. The findings strengthen the assumption that a quasi-one-dimensional channel is located in a deeper layer, which offers a reconciling explanation to previously conflicting interpretations.