Quantum simulation through atomic assembly

*Sander Otte
Delft University of Technology, The Netherlands

The magnetic and electronic properties of materials often find their origin in basic atomic- scale interactions. Yet, due to the large number of atoms involved, many phenomena can be very difficult to predict: we call these ’emergent’. The ability to build structures atom-by-atom by means of scanning tunneling microscopy (STM) provides an excellent platform to explore emergence as a function of system size. By properly tuning the anisotropy and coupling of magnetic atoms on a thin insulator, we have been able to engineer finite spin chains hosting spin waves [1] as well as the beginnings of a quantum phase transition at a critical magnetic field [2]. In a more recent experiment, we have engineered spin structures that are frustrated by design, exhibiting a spin spiral that can snap between different configurations. Unfortunately, the maximum size of assembled structures is often limited due to e.g. crystal impurity and crystal strain. In this talk, I will present a way to mitigate these limitations and show recent advances in sample preparation that will allow us to build much larger spin structures [3].

[1] A. Spinelli et al., Nature Materials 13 (2014) 782.

[2] R. Toskovic et al., Nature Physics 12 (2016) 656.

[3] J. Gobeil et al., Surface Science 679 (2019) 202.