Atom by atom: realization of robust corner states in an electronic breathing Kagome lattice

Quantum simulators are a versatile platform to study the behavior of novel quantum matter in a controlled way. Platforms based on ultracold atoms in optical lattices and photonic devices have led the field so far, but electronic quantum simulators are proving to be equally relevant. A tunable electronic platform is provided by the 2D electron gas at specific metal surfaces. By atomic-scale patterning of the surface in a scanning tunneling microscope, the electrons can be corralled into electronic lattices with nearly any geometry [1]. In this way, a variety of lattices defined by lattice geometry and bond strengths can be experimentally created and characterized. In particular, we will show the realization of an electronic breathing Kagome lattice. Alternating weak and strong bonds were engineered such that robust zero-energy states emerged at the corners of the lattice [2], determined by the chiral-symmetric edges of the structure [3]. By introducing defects, the zero-energy states were manipulated at will. This tunable approach holds promise for investigating other novel quantum phases of matter.

[1] K. K. Gomes et al., Nature 483, 306 (2012)
[2] S. N. Kempkes et al., Nature Materials 18, 1292 (2019)
[3] M. Jung et al., arXiv:2010.10299 [cond-mat.mes-hall] (2020)