Optical labyrinth II

In the grand finale of the escape room, you used quantum teleportation to “save” Oscar from Schrödinger’s box. In principle, quantum teleportation works just like the Transporter in Star Trek: no matter is transferred between two locations, only information about a body.  In a first step, a device measures all the particles in a body, temporarily destroying it. The quantum state of the body is  reconstructed at another location using local matter. In practice, we will likely never teleport a living being, because those are such incredibly complex systems. So far scientists have managed to teleport a dozen of particles, albeit at a distance of hundreds of kilometres, over satellite networks. 

To achieve quantum teleportation, we first must distribute entangled quantum particles to the initial and final destinations. In the puzzle, this was simulated by splitting a laser beam into two (with a beam splitter) and directing one beam to each of the sensors. In real experiments, a more involved process is needed to ensure that pairs of photons --- particles of light --- are correlated in a special way characteristic of quantum mechanics, called entanglement.

The special measurement we perform on the body to be transported also involves the entangled particles. It takes all the information about the quantum state of the body and breaks it into two puzzle pieces: one is the measurement outcome (the letters that appeared on the screen), and the other is the correlations between the photons at initial and final destination. In order to reconstruct the quantum state at the destination, we need to get the first piece there: what was the result of the measurement? That's why in the game you used a morse telegraph to send that information to Eve. Scientists can use anything for this step of communicating the measurement result: morse code, email, a phone call... but in practice they try to use ultra-fast communication.  Armed with that information, we can now apply a local operation at the destination and recreate the body (in your case by touching special letters under Eve's portrait). 

Thank you for saving Oscar! 

• Teleportation:Wikipedia 
• Progress in quantum teleportation: Nature Reviews Physics