TY - JOUR
T1 - A 2 × 2 quantum dot array with controllable inter-dot tunnel couplings
AU - Mukhopadhyay, Uditendu
AU - Dehollain, Juan Pablo
AU - Reichl, Christian
AU - Wegscheider, Werner
AU - Vandersypen, Lieven M.K.
PY - 2018/4/30
Y1 - 2018/4/30
N2 - 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.
AB - 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.
UR - http://resolver.tudelft.nl/uuid:50ce6abf-857c-455e-b8e7-c34a85c84619
UR - http://www.scopus.com/inward/record.url?scp=85046620441&partnerID=8YFLogxK
U2 - 10.1063/1.5025928
DO - 10.1063/1.5025928
M3 - Article
AN - SCOPUS:85046620441
SN - 0003-6951
VL - 112
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 18
M1 - 183505
ER -