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Résumé |
Feynman's original idea of using one quantum system that can be manipulated at will to simulate the
behavior of another more complex one has flourished during the last decades in the field of cold atoms.
More recently, this concept started to be developed in nanophotonics and in condensed matter. In this
talk, I will discuss a few recent experiments, in which 2D electron lattices were engineered on the
nanoscale. The first is the Lieb lattice [1,2], and the second is a Sierpinski gasket [3], which has dimension
D = 1.58. The realization of fractal lattices opens up the path to electronics in fractional dimensions.
Finally, I will show how to realize topological states of matter using the same procedure. We investigate the
robustness of the zero modes in a breathing Kagome lattice, which is the first experimental realization of a
designed electronic higher-order topological insulator [4]. Then, we investigate the importance of the
sample termination in determining the existence of topological edge modes in crystalline topological
insulators. We focus on the breathing Kekule lattice, with two different types of termination [5]. In all
cases, we observe an excellent agreement between the theoretical predictions and the experimental
results.\\
[1] M.R. Slot, T.S. Gardenier, P.H. Jacobse, G.C.P. van Miert, S.N. Kempkes, S.J.M. Zevenhuizen, C. Morais
Smith, D. Vanmaekelbergh, and I. Swart, "Experimental realisation and characterisation of an electronic
Lieb lattice", Nature Physics 13, 672 (2017).\\
[2] M. R. Slot et al., "p-band engineering in artificial electronic lattices", Phys. Rev. X 9, 011009 (2019).\\
[3] S.N. Kempkes, M.R. Slot, S.E. Freeney, S.J.M. Zevenhuizen, D. Vanmaekelbergh, I. Swart, and C. Morais
Smith, "Design and characterization of electronic fractals", Nature Physics 15, 127(2019).\\
[4] S.N. Kempkes, M. R. Slot, J. J. van den Broeke, P. Capiod, W. A. Benalcazar, D. Vanmaekelbergh, D.
Bercioux, I. Swart, and C. Morais Smith "Robust zero-energy modes 
in an electronic higher-order
topological insulator: the dimerized Kagome lattice", ArXiv: 1905.06053, to appear in Nature Materials
(2019).\\
[5] S. E. Freeney, J. J. van den Broeke, A. J. J. Harsveld van der Veen, I. Swart, and C. Morais Smith, "Edge
dependent topology in Kekulé lattices", submitted (2019). |
