Entanglement Metrology Using a Joint Readout of Superconducting Qubits

Understand

Accurate and precise detection of multi-qubit entanglement is key for the experimental development of quantum computation.

• Traditionally, non-classical correlations between entangled qubits are measured by counting coincidences between single-shot readouts of individual qubits.
• We report entanglement metrology using a single detection channel with direct access to ensemble-averaged correlations between two superconducting qubits.
• Following validation and calibration of this joint readout, we demonstrate full quantum tomography on both separable and highly-entangled two-qubit states produced on demand.