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 (5)

• Observation of parity-time symmetry breaking in a single spin system
• Dynamic polarization of single nuclear spins by optical pumping of NV color centers in diamond at room temperature
• Opening up the Quantum Three-Box Problem with Undetectable Measurements
• Translation of Lueders' "Uber die Zustandsanderung durch den Messprozess"
• Experimental violation of the Leggett-Garg inequality in a 3-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