Quantum Computation Toolbox for Decoherence‐Free Qubits Using Multi‐Band Alkali Atoms

摘要: We introduce protocols for designing and manipulating qubits with ultracold alkali atoms in 3D optical lattices. These are formed from two-atom spin superposition states that create a decoherence-free subspace immune to stray magnetic fields, dramatically improving coherence times while still enjoying the single-site addressability Feshbach resonance control of state-of-the-art atom systems. Our protocol requires no continuous driving or spin-dependent potentials, instead relies upon population higher motional band realize naturally tunable in-site exchange cross-site superexchange interactions. As proof-of-principle example their utility entanglement generation quantum computation, we show interactions can be used engineer 1D cluster states. Explicit experimental preparation manipulation also discussed, as well methods measuring more complex quantities such out-of-time-ordered correlation functions (OTOCs).