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MON: Monday Contributed Sessions

MON 23: Poster Session: Fundamental Aspects and Model Systems

MON 23.13: Poster

Monday, September 8, 2025, 18:30–20:30, ZHG Foyer 1. OG

Splitting and connecting singlets in atomic quantum circuits — •Lars Fischer, Zijie Zhu, Yann Kiefer, Samuel Jele, Marius Gächter, Giacomo Bisson, Konrad Viebahn, and Tilman Esslinger — Institute for Quantum Electronics & Quantum Center, ETH Zurich, 8093 Zurich, Switzerland

Large scale quantum computation relies on the configurable connection of qubits by system-wide error free transportation of quantum states. In this talk we present one way to coherently shuttle and manipulate quantum states in optical dynamical superlattices. By preparing atomic spin singlet pairs of fermionic potassium-40 in a lattice potential, we use a bi-directional quantized Thouless pump to transport, coherently split, and separate atomic pairs. We report a single-shift fidelity in our pumping mechanism of 99.78(3)% over 50 lattice sites.

Additionally, we implement tunable (SWAP)^α-gates with strongly repulsive interactions. When atoms moving in opposite directions meet on a double well, they undergo a superexchange interaction that continuously swaps their internal spin states. We use this gate set to coherently manipulate the quantum states in our system and interconnect large fractions of spin-singlet pairs. By applying a magnetic field gradient we observe multi-frequency singlet-triplet oscillations, which reveal complex final states from controlled quantum circuits. The presented scheme can be used as a tool to study full-system entanglement, quantum processing and sensing, and atom interferometry in optical lattices.

Keywords: Quantum Computation; Optical Lattice; Topological Pumping; Ultracold Atoms; Particle Entanglement