Fig. 2: The entropies of different states as functions of the noise level and resolution.
From: Semi-device-independent quantum random number generator with a broadband squeezed state of light
a The dashed line (Hsqu) represents the lower bound on the conditional min-entropies of the anti-squeezed quadrature of the squeezed state, the light blue (\({H}_{\min }\)) and orange curves (Hlow) represent the min-entropy of the thermal state and the lower bound on the conditional min-entropy of the thermal state respectively. All the curves are estimated with a precision δ = 0.01536, and the noise levels are set in units of shot noise. The noise level represents the additional noise for thermal state and pure quantum noise for squeezed state, respectively. b The lower bound on the conditional min-entropy versus the resolution of the oscilloscope for the vacuum state, a 3.8 dB squeezed state and 8.0 dB squeezed state. The precision is set as δ = 0.01536. The marks show the amount of extractable secure bits in our experiment.
