Quantum fingerprinting with coherent states for multiple clients

Farid Mansurovich Ablayev, Alexander Vasiliev

Ahmed Shokry, Moustafa A. Youssef

Benjamin Lovitz

Xiaoqing Zhong, Feihu Xu, Hoi-Kwong Lo +1 more

Quantum communication complexity explores the minimum amount of communication required to achieve certain tasks using quantum states. One representative example is quantum fingerprinting, in which the minimum amount of communication could be exponentially smaller than the classical fingerprinting. Here, we propose a quantum fingerprinting protocol where coherent states and channel multiplexing are used, with simultaneous detection of signals carried by multiple channels. Compared with an existing coherent quantum fingerprinting protocol, our protocol could consistently reduce communication time and the amount of communication by orders of magnitude by increasing the number of channels. Our proposed protocol can even beat the classical limit without using superconducting-nanowire single photon detectors. We also report a proof-of-concept experimental demonstration with six wavelength channels to validate the advantage of our protocol in the amount of communication. The experimental results clearly prove that our protocol not only surpasses the best-known classical protocol, but also remarkably outperforms the existing coherent quantum fingerprinting protocol.

Andreas Winter

Niraj Kumar, Eleni Diamanti, Iordanis Kerenidis

We provide an example of a communication model and a distributed task, for which there exists a realistic quantum protocol that is asymptotically more efficient than any classical protocol, both in the communication and the information resources. For this, we extend a recently proposed coherent state mapping for quantum communication protocols, study the use of coherent state fingerprints over multiple channels, and show their role in the design of an efficient quantum protocol for estimating the Euclidean distance of two real vectors within a constant factor.