Classical Cost of Transmitting a Qubit
Abstract
We consider general prepareandmeasure scenarios in which Alice can transmit qubit states to Bob, who can perform general measurements in the form of positive operatorvalued measures (POVMs). We show that the statistics obtained in any such quantum protocol can be simulated by the purely classical means of shared randomness and two bits of communication. Furthermore, we prove that two bits of communication is the minimal cost of a perfect classical simulation. In addition, we apply our methods to Bell scenarios, which extends the wellknown Toner and Bacon protocol. In particular, two bits of communication are enough to simulate all quantum correlations associated to arbitrary local POVMs applied to any entangled twoqubit state.
 Publication:

Physical Review Letters
 Pub Date:
 March 2023
 DOI:
 10.1103/PhysRevLett.130.120801
 arXiv:
 arXiv:2207.02244
 Bibcode:
 2023PhRvL.130l0801R
 Keywords:

 Quantum Physics
 EPrint:
 4 pages main text, 10 pages appendix, matches published version