Experimental violation of the Leggett-Garg inequality with a single-spin system

Abstract

Investigation the boundary between quantum mechanical description and classical realistic view is of fundamental importance. The Leggett-Garg inequality provides a criterion to distinguish between quantum systems and classical systems, and can be used to prove the macroscopic superposition state. A larger upper bound of the LG function can be obtained in a multi-level system. Here, we present an experimental violation of the Leggett-Garg inequality in a three-level system using nitrogen-vacancy center in diamond by ideal negative result measurement. The experimental maximum value of Leggett-Garg function is $K_3^{exp}=1.625\pm 0.022$ which exceeds the Lüders bound with a $5\sigma$ level of confidence.

References in corpus (14)

• Observation of parity-time symmetry breaking in a single spin system
• Leggett-Garg Inequalities
• Dynamic polarization of single nuclear spins by optical pumping of NV color centers in diamond at room temperature
• Experimental violation of a Bell's inequality in time with weak measurement
• Violation of a Leggett-Garg inequality with ideal non-invasive measurements
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• Experimental Violation of Two-Party Leggett-Garg Inequalities with Semi-weak Measurements
• Opening up the Quantum Three-Box Problem with Undetectable Measurements
• Temporal quantum correlations and Leggett-Garg inequalities in multi-level systems
• Translation of Lueders' "Uber die Zustandsanderung durch den Messprozess"
• Violation of Entropic Leggett-Garg Inequality in Nuclear Spins
• Maximum violations of the quantum-witness equality
• Experimental violation of the Leggett-Garg inequality in a 3-level system
• Enhanced violations of Leggett-Garg inequalities in an experimental three-level system

Cited by in corpus (4)

• Experimental demonstration of enhanced violations of Leggett-Garg inequalities in a $\mathcal{P}\mathcal{T}$-symmetric trapped-ion qubit
• Experimental violation of Leggett-Garg inequality in a three-level trapped-ion system
• Observation of quantum temporal correlations well beyond Luders bound
• Fractional Conformal Map, Qubit Dynamics and the Leggett-Garg Inequality