7 papers
Quantifying Measurement Objectivity: A Retrodictive Approach
Jiaxi Kuang, Teruaki Nagasawa, Kensei Torii +1
When can one interpret the outcomes of a quantum measurement as revealing a pre-existing objective property? Using the recently developed formalism of quantum measurement retrodict…
A quantum entropy production operator
Ge Bai, Francesco Buscemi, Valerio Scarani
We introduce a fully quantum notion of entropy production based on the non-commutative extension of the classical log-ratio between forward and reverse processes. Given a pair of q…
Macroscopicity and observational deficit in states, operations, and correlations
Teruaki Nagasawa, Eyuri Wakakuwa, Kohtaro Kato +1
To understand the emergence of macroscopic irreversibility from microscopic reversible dynamics, the idea of coarse-graining plays a fundamental role. In this work, we develop a un…
On the generic increase of observational entropy in isolated systems
Teruaki Nagasawa, Kohtaro Kato, Eyuri Wakakuwa +1
Observational entropy -- a quantity that unifies Boltzmann's entropy, Gibbs' entropy, von Neumann's macroscopic entropy, and the diagonal entropy -- has recently been argued to pla…
Quantum Bayes' rule and Petz transpose map from the minimum change principle
Ge Bai, Francesco Buscemi, Valerio Scarani
Bayes' rule, which is routinely used to update beliefs based on new evidence, can be derived from a principle of minimum change. This principle states that updated beliefs must be…
Port-based telecloning of an unknown quantum state
Reiji Okada, Kohtaro Kato, Francesco Buscemi
Telecloning is a protocol introduced by Murao et al. [Phys. Rev. A 59, 156 (1999)] to distribute copies of an unknown quantum state to many receivers in a way that beats the trivia…