Print Email Facebook Twitter Ab initio exact diagonalization simulation of the Nagaoka transition in quantum dots Title Ab initio exact diagonalization simulation of the Nagaoka transition in quantum dots Author Wang, Yao (Harvard University) Dehollain, Juan Pablo (Kavli institute of nanoscience Delft; University of Technology Sydney) Liu, Fang (Massachusetts Institute of Technology) Mukhopadhyay, U. (TU Delft QCD/Vandersypen Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Rudner, Mark S. (University of Copenhagen) Vandersypen, L.M.K. (TU Delft TU Delft Library; TU Delft QCD/Vandersypen Lab; TU Delft QN/Vandersypen Lab) Demler, Eugene (Harvard University) Department TU Delft Library Date 2019 Abstract Recent progress of quantum simulators provides insight into the fundamental problems of strongly correlated systems. To adequately assess the accuracy of these simulators, the precise modeling of the many-body physics, with accurate model parameters, is crucially important. In this paper, we employed an ab initio exact diagonalization framework to compute the correlated physics of a few electrons in artificial potentials. We apply this approach to a quantum-dot system and study the magnetism of the correlated electrons, obtaining good agreement with recent experimental measurements in a plaquette. Through control of dot potentials and separation, including geometric manipulation of tunneling, we examine the Nagaoka transition and determine the robustness of the ferromagnetic state. While the Nagaoka theorem considers only a single-band Hubbard model, in this work we perform extensive ab initio calculations that include realistic multiorbital conditions in which the level splitting is smaller than the interactions. This simulation complements the experiments and provides insight into the formation of ferromagnetism in correlated systems. More generally, our calculation sets the stage for further theoretical analysis of analog quantum simulators at a quantitative level. To reference this document use: http://resolver.tudelft.nl/uuid:305a7400-3f5b-4780-8c83-b331873927ce DOI https://doi.org/10.1103/PhysRevB.100.155133 ISSN 2469-9950 Source Physical Review B, 100 (15) Part of collection Institutional Repository Document type journal article Rights © 2019 Yao Wang, Juan Pablo Dehollain, Fang Liu, U. Mukhopadhyay, Mark S. Rudner, L.M.K. Vandersypen, Eugene Demler Files PDF PhysRevB.100.155133.pdf 1.92 MB Close viewer /islandora/object/uuid:305a7400-3f5b-4780-8c83-b331873927ce/datastream/OBJ/view