Chronological feed of everything captured from Jeff Thompson.
This paper introduces a scalable postselection approach to reduce the overhead associated with quantum error correction. By directly postselecting sub-circuits based on decoder soft information and utilizing a new metric called the partial gap, this method significantly improves the logical error rate. The technique demonstrates a substantial reduction in overhead for implementing logical gates via cluster state teleportation.
The research demonstrates a significant increase in Rydberg atom lifetimes using a cryogenic blackbody radiation shield. This advancement facilitates improved coherent manipulation of ground-Rydberg qubits and mitigates dephasing from light intensity fluctuations. Longer Rydberg lifetimes directly contribute to higher fidelity two-qubit gates, addressing a critical error source in neutral-atom quantum computing.
This paper demonstrates that postselecting against exponentially unlikely syndrome patterns in toric codes significantly reduces logical failure rates. The mechanism leverages the statistical distribution of these syndromes, achieving scalable accuracy gains. The concept is generalizable to other topological stabilizer codes and situations where decoding failure probability adheres to a large deviation principle.
This work demonstrates coherent optical and spin control of a pair of interacting Er³⁺ ions and a nuclear spin ancilla in the solid state, overcoming the longstanding challenge of individually addressing spins at nanometer-scale separations. Rather than relying on spatial resolution, the approach leverages the narrow homogeneous optical linewidths of rare-earth ions to resolve emitters in the frequency domain, decoupling addressability from physical proximity. The team realizes two-qubit electron-electron gates, repeated quantum non-demolition (QND) measurements, and electron-nuclear gates for coherent qubit storage — with nuclear spin coherence preserved through electron spin readout. These results establish a scalable pathway toward massively multiplexed quantum network nodes.
This paper extends microwave spectroscopy and multichannel quantum defect theory (MQDT) modeling of ytterbium Rydberg states (6snℓ) in ¹⁷⁴Yb and ¹⁷¹Yb to include f (ℓ=3) and g (ℓ=4) series, building more complete models of a structurally complex atom. Key findings include p-f channel mixing in odd-parity ¹⁷¹Yb Rydberg states and spin-orbit dominance over exchange interaction in the 6sng series, requiring a jj-coupled basis for accurate description. Model predictions for Landé g-factors and static dipole polarizabilities show excellent agreement with experimental measurements, validating the MQDT framework. These results provide actionable parameters for engineering high-fidelity two-qubit entangling gates in ytterbium-based neutral atom quantum processors.