Experimental demonstration of a quantum receiver beating the standard quantum limit at telecom wavelength

S Izumi, JS Neergaard-Nielsen, S Miki, H Terai… - Physical Review …, 2020 - APS
Physical Review Applied, 2020APS
Discrimination of coherent states beyond the standard quantum limit (SQL) is an important
task not only for quantum information processing but also for optical coherent
communication. To optimize long-distance optical fiber networks, it is of practical importance
to develop a quantum receiver beating the SQL and approaching the quantum bound at
telecom wavelength. In this paper, we experimentally demonstrate a receiver beating the
conventional SQL at telecom wavelength. Our receiver is composed of a displacement …
Abstract
Discrimination of coherent states beyond the standard quantum limit (SQL) is an important task not only for quantum information processing but also for optical coherent communication. To optimize long-distance optical fiber networks, it is of practical importance to develop a quantum receiver beating the SQL and approaching the quantum bound at telecom wavelength. In this paper, we experimentally demonstrate a receiver beating the conventional SQL at telecom wavelength. Our receiver is composed of a displacement operation, a single-photon counter, and a real-time adaptive-feedback operation. By using a high-performance single-photon detector operating at the telecom wavelength, we achieve a discrimination error beyond the SQL. The demonstration in the telecom band is an enabler for quantum and classical communication beyond the SQL using a coherent state alphabet, and we envision that the technology can be used for long-distance quantum-key distribution, effective quantum-state preparation, and quantum estimation.
American Physical Society
Showing the best result for this search. See all results