Quantum algorithm for distributed clock synchronization
The clock synchronization problem is to determine the time difference Delta between two spatially separated clocks. When message delivery times between the two clocks are uncertain, O(2(2n)) classical messages must be exchanged between the clocks to determine n digits of Delta. On the other hand, as we show, there exists a quantum algorithm to obtain n digits of Delta while communicating only O(n) quantum messages.
Chuang
IL
IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.