Figure 1

In the quantum eraser experiment, we recover the interference pattern by choosing an appropriate measurement basis. (a, d) The quantum eraser experiments using a Mach–Zehnder interferometer (MZI) and a spontaneous parametric down-conversion (SPDC), an alternative setup to the double-slit experiment: upon entering the first beamsplitter (BS), the original photon is split into upper-path (red) and lower-path (blue). Each path transforms into a signal-idler photons pair by passing through the SPDC. The signal photons (s) interfere at the second BS and are measured by D₁₍₂₎. The idler photons are measured by D₃₍₄₎ without an eraser in (a) and with an eraser in (d). (b, e) Quantum circuit for the experiment in (a, d), respectively. (c, f) Experiment results obtained from the IBM Vigo quantum computer shown as blue bars and the theoretical value showed as red lines. The device error is estimated at 3.7%, while standard error from the mean of 8192 shots is minimal at 0.5%