Seminarium Fizyki Ciała Stałego

The recent development of precise phosphorus donor placement in silicon [1,2] has attracted attention to the chains and arrays of such sites. They have already proven to be well suited for quantum simulation of the Extended Hubbard [3] and SSH [4] models and are of major interest for future quantum-information devices.In the experiment, gated systems of a few sites are studied electrically by measuring the current while sweeping gate voltages. The theory aims to simulate such diagrams and provide a two-way correspondence between the system and the simulated model. Thus, the need for a non-equilibrium transport theory of dopant systems arises. As the precision of donor placement approaches the level of creating single-atom sites, calculations of hopping and interaction matrix elements between such sites are also needed.I will present our recent work on evaluating hopping integrals between such donors and simulating the transport properties of their arrays. I will describe the method based on Bardeen's tunneling theory, which enables us to calculate hopping between various orbitals based on their wave functions only [5]. Our approach to transport is based on combining exact diagonalization with non-equilibrium Green's functions and allows the calculation of currents and other observables in the arrays. We study some of these effects to better understand the transport investigations of experimentally realized 3×3 arrays [3]. Among other things, we predict that such systems should be surprisingly immune to site disorder.[1] M. Fuechsle et al., Nature Nanotech. 7, 242 (2012).[2] J. Wyrick et al., Adv. Funct. Mater. 29, 1903475 (2019).[3] X. Wang et al., Nature Commun. 13, 6824 (2022).[4] Y. Chung et al., Nature 606, 694 (2022).[5] M.G., M. Zieliński, Phys. Rev. B 106, 115426 (2022).