Anton Zeilinger

<p>It was a joyful moment when I rediscovered my old notebooks. I would not have searched for them without the dOCUMENTA (13) notebook publishing project. When reading these old notes now, I am surprised how many ideas they already contain and how they developed, building unconsciously one on the other. I had no memory of the level of detail in which some of these ideas had already been analyzed in the early notebooks.</p> <p>The books I found cover a three-year period beginning in late 1992. In my scientific life, this was a crucial time. It was the time when key steps were taken toward my later work on multiphoton states, on quantum teleportation, and on all-optical quantum computation.</p> <p>I had carried out experiments on the foundation of quantum me­chanics before. These early experiments were all done with neutrons. In 1990, I had moved to Innsbruck, where I was given empty laboratories and enough financial support to start a new research program. Most importantly, I was lucky to have a group of excellent young physicists working with me. And then, in 1993–94, my laboratories in Innsbruck began to go into operation. There, with my students and post-docs, I began my own first experiments with entangled photon pairs…</p> <p> </p>