Freiburg 2024 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 53: Quantum Control
Q 53.6: Vortrag
Donnerstag, 14. März 2024, 15:45–16:00, HS 3118
Optimal control methods for two-qubit gates in optical lattices — •Juhi Singh1,2, Felix Motzoi1, Tommaso Calarco1,2,3, and Robert Zeier1 — 1Forschungszentrum Jülich GmbH, Peter Grünberg Institute, Quantum Control (PGI-8), 52425 Jülich, Germany — 2Institute for Theoretical Physics, University of Cologne, 50937 Köln, Germany — 3Dipartimento di Fisica e Astronomia, Università di Bologna, 40127 Bologna, Italy
We use quantum optimal control to identify fast collision-based two-qubit gates in ultracold atoms trapped in superlattices based on classical Fermi-Hubbard simulations. We manipulate the hopping and interaction strengths inherent in the Fermi-Hubbard model by optimizing the lattice depth and the scattering length. We show that a significant speedup can be achieved by optimizing the lattice depths in a time-dependent manner, as opposed to maintaining a fixed depth. We obtain non-adiabatic fast gates by including higher bands of the Hubbard model in the optimization. Furthermore, in addition to two-qubit states, our optimized control pulses retain their effectiveness for one, three, or four atoms in the superlattice. We compare our Fermi-Hubbard approach with real-space simulations using Wannier functions.
Keywords: Quantum control; ultracold atoms; optical lattice; gate optimization; Hubbard