Quantum clock synchronization based on shared prior entanglement

Phys Rev Lett. 2000 Aug 28;85(9):2010-3. doi: 10.1103/PhysRevLett.85.2010.

Abstract

We demonstrate that two spatially separated parties (Alice and Bob) can utilize shared prior quantum entanglement, and classical communications, to establish a synchronized pair of atomic clocks. In contrast to classical synchronization schemes, the accuracy of our protocol is independent of Alice's or Bob's knowledge of their relative locations or of the properties of the intervening medium.