Implementation of Multiparty quantum clock synchronization

TL;DR

This paper reports the experimental implementation of multiparty quantum clock synchronization protocols using four-qubit NMR, demonstrating their practical feasibility and comparing their accuracy.

Contribution

First experimental realization of Krco and Ben-Av multiparty QCS algorithms using NMR technology, validating theoretical predictions and comparing their accuracy.

Findings

Ben-Av multiparty QCS is more accurate than Krco's.

Experimental results align well with theoretical models.

Demonstrates feasibility of multiparty QCS with NMR.

Abstract

The quantum clock synchronization (QCS) is to measure the time difference among the spatially separated clocks with the principle of quantum mechanics. The first QCS algorithm proposed by Chuang and Jozsa is merely based on two parties, which is further extended and generalized to the multiparty situation by Krco and Paul. They present a multiparty QCS protocol based upon W states that utilizes shared prior entanglement and broadcast of classical information to synchronize spatially separated clocks. Shortly afterwards, Ben-Av and Exman came up with an optimized multiparty QCS using Z state. In this work, we firstly report an implementation of Krco and Ben-AV multiparty QCS algorithm using a four-qubit Nuclear Magnetic Resonance (NMR). The experimental results show a great agreement with the theory and also prove Ben-AV multiparty QCS algorithm more accurate than Krco.