Weird, it works for me. You can use any of the other published links in the sibling comments. The name of the paper is "Quantum Limits in Optical Communications" by Banaszek

I think it is https://arxiv.org/abs/2002.05766.

I think it's this one:

https://opg.optica.org/jlt/viewmedia.cfm?uri=jlt-38-10-2741&...

Quantum Limits in Optical Communications

Konrad Banaszek, Ludwig Kunz, Michał Jachura, and Marcin Jarzyna