Fig. 1: Schematics of the setup.
From: Measuring statistics-induced entanglement entropy with a Hong–Ou–Mandel interferometer
A Schematics of the experimental setup. B The corresponding theoretical schematics. The Hong–Ou–Mandel interferometer consists of two sources (\({{{{{{{{\mathcal{S}}}}}}}}}_{A}\) and \({{{{{{{{\mathcal{S}}}}}}}}}_{B}\)) and two diluted middle arms (\({{{{{{{{\mathcal{M}}}}}}}}}_{A}\), \({{{{{{{{\mathcal{M}}}}}}}}}_{B}\)) via transmission probabilities \({{{{{{{{\mathcal{T}}}}}}}}}_{A}\) and \({{{{{{{{\mathcal{T}}}}}}}}}_{B}\) (with two quantum point contacts). The currents are measured at drains \({{{{{{{{\mathcal{D}}}}}}}}}_{A}\) and \({{{{{{{{\mathcal{D}}}}}}}}}_{B}\). For later convenience, we call the source arms after the diluters as \({\tilde{{{{{{{{\mathcal{D}}}}}}}}}}_{A}\) and \({\tilde{{{{{{{{\mathcal{D}}}}}}}}}}_{B}\). For simplicity, the two sources are equally biased: VA = VB = Vbias. The red line separates the two entangled subsystems, A (the two upper arms with labels A) and B (the two lower arms with labels B). C Distribution functions of the two middle arms (\({{{{{{{{\mathcal{M}}}}}}}}}_{A}\) and \({{{{{{{{\mathcal{M}}}}}}}}}_{B}\)) for non-interacting fermions (fA, fB, respectively) at zero temperature (carrying shot noise). The double-step distributions are modified when the filling factor is larger than one, with an added interaction between the two modes on each edge [Eq. (S34) of Supplementary Information Sect. S2].
