Quantum Journal

High-Fidelity Inter-Species Rydberg Gates with Two-Photon Driving

Recently, neutral atom arrays have become known for their promising potential in quantum information processing. High-fidelity entangling operations are typically achieved by exciting atoms to high-lying Rydberg states through two-photon processes. To improve the performance of these systems at the hardware level, dual-species strategies have been applied to enhance readout, error correction, and reloading in neutral atom systems. However, the i...

Efficiently computable bounds on the energy-constrained quantum reading capacity

In quantum reading, classical messages are encoded in sequences of quantum channels and recovered by probing the channels and processing their outputs. We study the reading capacity of a finite family of finite-dimensional channels under an average constraint on the probing energy, allowing arbitrary adaptive operations between channel uses. Using an input-dependent chain rule for the Belavkin-Staszewski relative entropy, we derive a converse bo...

DARPA Selects Atom Computing, Diraq, IBM, and IonQ for Final Stage C Verification under Quantum Benchmarking Initiative

DARPA has selected Atom Computing, Diraq, IBM, and IonQ for Stage C of its Quantum Benchmarking Initiative (QBI) to verify the performance of their fault-tolerant quantum computing architectures. This stage involves direct physical testing and empirical validation of their hardware, aiming to assess their potential for utility-scale operation by 2033. The chosen companies represent diverse qubit technologies, including neutral atoms, silicon spin qubits, superconducting transmons, and trapped...

Error semitransparent universal control of a bosonic logical qubit