Print Email Facebook Twitter A 2 × 2 quantum dot array with controllable inter-dot tunnel couplings Title A 2 × 2 quantum dot array with controllable inter-dot tunnel couplings Author Mukhopadhyay, U. (TU Delft QCD/Vandersypen Lab) Dehollain Lorenzana, J.P. (TU Delft QCD/Vandersypen Lab) Reichl, Christian (ETH Zürich) Wegscheider, Werner (ETH Zürich) Vandersypen, L.M.K. (TU Delft QCD/Vandersypen Lab; TU Delft QN/Vandersypen Lab) Date 2018-04-30 Abstract The interaction between electrons in arrays of electrostatically defined quantum dots is naturally described by a Fermi-Hubbard Hamiltonian. Moreover, the high degree of tunability of these systems makes them a powerful platform to simulate different regimes of the Hubbard model. However, most quantum dot array implementations have been limited to one-dimensional linear arrays. In this letter, we present a square lattice unit cell of 2 × 2 quantum dots defined electrostatically in an AlGaAs/GaAs heterostructure using a double-layer gate technique. We probe the properties of the array using nearby quantum dots operated as charge sensors. We show that we can deterministically and dynamically control the charge occupation in each quantum dot in the single- to few-electron regime. Additionally, we achieve simultaneous individual control of the nearest-neighbor tunnel couplings over a range of 0-40 μeV. Finally, we demonstrate fast (∼1 μs) single-shot readout of the spin state of electrons in the dots through spin-to-charge conversion via Pauli spin blockade. These advances pave the way for analog quantum simulations in two dimensions, not previously accessible in quantum dot systems. To reference this document use: http://resolver.tudelft.nl/uuid:50ce6abf-857c-455e-b8e7-c34a85c84619 DOI https://doi.org/10.1063/1.5025928 ISSN 0003-6951 Source Applied Physics Letters, 112 (18) Part of collection Institutional Repository Document type journal article Rights © 2018 U. Mukhopadhyay, J.P. Dehollain Lorenzana, Christian Reichl, Werner Wegscheider, L.M.K. Vandersypen Files PDF 1.5025928.pdf 1.15 MB Close viewer /islandora/object/uuid:50ce6abf-857c-455e-b8e7-c34a85c84619/datastream/OBJ/view