Demonstration of entanglement-by-measurement of solid state qubits

Abstract

Projective measurements are a powerful tool for manipulating quantum states. In particular, a set of qubits can be entangled by measurement of a joint property such as qubit parity. These joint measurements do not require a direct interaction between qubits and therefore provide a unique resource for quantum information processing with well-isolated qubits. Numerous schemes for entanglement-by-measurement of solid-state qubits have been proposed, but the demanding experimental requirements have so far hindered implementations. Here we realize a two-qubit parity measurement on nuclear spins in diamond by exploiting the electron spin of a nitrogen-vacancy center as readout ancilla. The measurement enables us to project the initially uncorrelated nuclear spins into maximally entangled states. By combining this entanglement with high-fidelity single-shot readout we demonstrate the first violation of Bells inequality with solid-state spins. These results open the door to a new class of experiments in which projective measurements are used to create, protect and manipulate entanglement between solid-state qubits.

6 pages, 4 figures

References in corpus (8)

• Quantum Computing
• High-fidelity projective readout of a solid-state spin quantum register
• Quantum Teleportation Between Distant Matter Qubits
• Solid state quantum memory using the 31P nuclear spin
• Charge detection enables free-electron quantum computation
• Parity meter for charge qubits: an efficient quantum entangler
• Coherence of an optically illuminated single nuclear spin qubit
• Entangling spins by measuring charge: a parity-gate toolbox

Cited by in corpus (1)

• Diamond Nanophotonics