One-Shot Coherence Dilution

TL;DR

This paper develops a one-shot theory for quantum coherence dilution, providing operational measures and analyzing finite-resource effects, with implications for quantum information tasks like key distribution.

Contribution

It introduces the first one-shot coherence dilution framework and coherence monotones, extending to asymptotic cases for various incoherent operations.

Findings

Defined coherence monotones with operational meaning

Established one-shot coherence cost bounds

Extended results to asymptotic coherence dilution

Abstract

Manipulation and quantification of quantum resources are fundamental problems in quantum physics. In the asymptotic limit, coherence distillation and dilution have been proposed by manipulating infinite identical copies of states. In the non-asymptotic setting, finite data-size effects emerge, and the practically relevant problem of coherence manipulation using finite resources has been left open. This letter establishes the one-shot theory of coherence dilution, which involves converting maximally coherent states into an arbitrary quantum state using maximally incoherent operations, dephasing-covariant incoherent operations, incoherent operations, or strictly incoherent operations. We introduce several coherence monotones with concrete operational interpretations that estimate the one-shot coherence cost --- the minimum amount of maximally coherent states needed for faithful coherence dilution. Furthermore, we derive the asymptotic coherence dilution results with maximally incoherent operations, incoherent operations, and strictly incoherent operations as special cases. Our result can be applied in the analyses of quantum information processing tasks that exploit coherence as resources, such as quantum key distribution and random number generation.