Figure 1

Experimental setup for demonstrating temporal steering.

Here we use abbreviations: BS for beam splitter, PBS for polarising BS, NDF for neutral density filter of tunable transmittance τ, BD_n for beam dividers, PC_n for the polarisation controllers compensating polarisation rotation in the fibers, Q_n for quarter-wave plates, H_n for half-wave plates, SPCM for single-photon counting module, SM for the 15 m long single-mode optical fiber which forms a delay line of t = 80 ns (this is larger than the 50 ns long dead time of the SPCM). Alice prepares the initial state by rotating a H-polarised photon with Q_A and H_A plates. Bob performs state analysis by setting his measurement basis with H_B and Q_B, and detecting the incoming photon in one of the orthogonal polarisation states.