Fidelity measurement of a multiqubit cluster state with minimal effort

Abstract

The size of the Hilbert space for a multiqubit state scales exponentially with the number of constituent qubits. Often this leads to a similar exponential scaling of the experimental resources required to characterize the state. Contrary to this, we propose a physically-motivated method for experimentally assessing the fidelity of an important class of entangled states known as cluster states. The proposed method always yields a lower bound of the fidelity with a number of measurement settings scaling only linearly with the system size, and is tailored to correctly account for the errors most likely to occur in experiments. For one-dimensional cluster states, the constructed fidelity measure is tight to lowest order in the error probability for experimentally realistic noise sources and thus closely matches the true fidelity. Furthermore, it is tight for the majority of higher-order errors, except for a small subset of certain non-local multiqubit errors irrelevant in typical experimental situations. The scheme also performs very well for higher-dimensional cluster states, including correctly the majority of experimentally relevant errors.

References in corpus (21)

• Entanglement detection
• Scalable multi-particle entanglement of trapped ions
• 14-qubit entanglement: creation and coherence
• Resource-efficient linear optical quantum computation
• Efficient quantum state tomography
• Experimental entanglement of six photons in graph states
• Direct Fidelity Estimation from Few Pauli Measurements
• Multiparty quantum state sharing of an arbitrary two-particle state with Einstein-Podolsky-Rosen pairs
• Detecting Genuine Multipartite Entanglement with Two Local Measurements
• Experimental entanglement of a six-photon symmetric Dicke state
• Experimental Analysis of a 4-Qubit Cluster State
• Entanglement Detection in the Stabilizer Formalism
• Permutationally invariant quantum tomography
• Experimental Quantum Secret Sharing and Third-Man Quantum Cryptography
• Experimental demonstration of four-party quantum secret sharing
• Toolbox for entanglement detection and fidelity estimation
• Realization and characterization of a 2-photon 4-qubit linear cluster state
• Self-guided quantum tomography
• Machine learning assisted quantum state estimation
• Resource requirements for efficient quantum communication using all-photonic graph states generated from a few matter qubits
• Optimal verification of stabilizer states

Cited by in corpus (7)

• Fusion of deterministically generated photonic graph states
• Influence of noise in entanglement-based quantum networks
• Extracting GHZ states from linear cluster states
• Verifiable measurement-based quantum random sampling with trapped ions
• Efficient generation of entangled multi-photon graph states from a single atom
• Detecting genuine multipartite entanglement in multi-qubit devices with restricted measurements
• Evaluating Pauli errors on cluster states by weighted distances