Quantum-Teleport | We explain quantum teleportation and implement it in Q

Quantum-Teleport is a C# library. Quantum-Teleport has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

For a quick primer on quantum computing and the use of the Q# programming language, see . I'll be assuming some small amount of comfort with the ideas laid out there. The main idea of quantum teleportation is as follows: Given two qubits q1 and q2 (not necessarily being held in the same location), transfer the state of q1 to q2. We are allowed to prepare whatever quantum or classical states we want beforehand, and we are allowed to communicate any number of classical bits in order to transfer our state from q1 to q2. We require that q1 and q2 do not end up entangled with each other, i.e. simply entangling q1 and q2 via "CNOT(q1, q2); Hadamard(q1);" doesn't count as a solution. In other words, we'd like to be able to reset q1 after this process without affecting q2. For ordinary bits, this would be no problem: Simply read q1, send the information to the facility holding q2, and have someone at that facility set q2 to that value. This won't work with a quantum system because to read q1 is to measure it, so if q1 were in some superposition of |0> and |1> and we measured q1 as |0>, then setting q2 to |0> would not be the same as setting q2 to the original state of q1. Equally fundamentally, even if we did know the state of q1, unless q1 were particularly simple it could take an infinite number of classical bits to write this state down. It's worth mentioning the no-cloning theorem, which says that it's impossible to create a perfect copy of an unknown quantum state. This implies that there's no way to solve this problem without somehow changing q1. It implies a bit more - namely, if we could transfer the state of q1 to q2, then we can't in principle do anything to q1 to get it back to the state it used to be in without doing something to q2 which knocks it out of its new state. This serves as a nice hint for how quantum teleportation might be done: (1) Start out with q1 and q2, where q1 is in some unknown state and q2 is (crucially) in some known state. (2) Mess around with entanglement and superposition a bit. (3) End with q1 in a known state and q2 in the state q1 used to hold.