Fig. 3: Example of the experimental results for a single value of time t = 26 ns = 7π/6Ω.
From: Interferometry of quantum correlation functions to access quasiprobability distribution of work
a Characteristic function \({\mathcal{G}}(u)\) [Eq. (4)] of the KDQ distribution of work. The real (imaginary) part of the characteristic function, shown in blue (orange), is the result of measuring the expectation value of σx(y) with respect to the state of the auxiliary qubit in the interferometric scheme. The expectation value 〈σx(y)〉 is the photoluminescence (PL) intensity normalized with respect to the reference intensity of the eigenstates of the observable σx(y). b By applying a Fourier transform to \({\mathcal{G}}(u)\), we are able to reconstruct the KDQ distribution P(W) of work. The error bars are the standard deviation of the FFT calculated as the mean (over all the data) standard deviation of \({\mathcal{G}}(u)\). The values we are interested in are those where W = ± ω, 0 (indicated with vertical dashed lines), which are the only allowed energy variations for the two-level system evolving under the Hamiltonian H(t) [Eq. (8)]. Note that the real and imaginary parts of \({\mathcal{G}}(u)\) are both necessary to obtain the real or imaginary parts of the work distribution P(W).
