Erratum: Waveguide QED: Power spectra and correlations of two photons scattered off multiple distant qubits and a mirror [Phys. Rev. A 91, 053845 (2015)]

Figure 14

Photon correlations $g_2\left(t\right)$ of a single qubit coupled to a semi-infinite waveguide with resonant incoming photons ($k={\omega }_0$) in the non-Markovian regime ($k_{0}a=20\pi$ and $20.5\pi$). For $k_{0}a=20.5\pi$, the full non-Markovian result calculated from scattering theory (the blue points) or the finite-difference time-domain [(FDTD) [1], the black curve] differs substantially from the Markovian result (the red curve) [as in Fig. 14(a)]. For $k_{0}a=20\pi$, we check that the FDTD approach (the magenta dashed line) yields the exact result $g_2\left(t\right)=1$, which is obtained because the qubit decouples. [Parameters: The qubit frequency is ${\omega }_0=100\mathrm{\Gamma }$, and the FDTD step size is $\mathrm{\Delta }={\lambda }_0/240$.]