Quasi-inversion of quantum and classical channels in finite dimensions
نویسندگان
چکیده
Abstract We introduce the concept of quasi-inverse quantum and classical channels, prove general properties these inverses determine them for a large class channels acting in an arbitrary finite dimension. Therefore we extend previous results Karimipour et al (2020 Phys. Rev. A 101 032109) to dimensional domain. demonstrate how application proposed scheme can increase on average fidelity between given random pure state its image transformed by channel followed quasi-inversion.
منابع مشابه
Quasi-Superactivation of Classical Capacity of Zero-Capacity Quantum Channels
One of the most surprising recent results in quantum Shannon theory is the superactivation of the quantum capacity of a quantum channel. This phenomenon has its roots in the extreme violation of additivity of the channel capacity and enables to reliably transmit quantum information over zerocapacity quantum channels. In this work we demonstrate a similar effect for the classical capacity of a q...
متن کاملErgodic and mixing quantum channels in finite dimensions
The paper provides a systematic characterization of quantum ergodic and mixing channels in finite dimensions and a discussion of their structural properties. In particular, we discuss ergodicity in the general case where the fixed point of the channel is not a full-rank (faithful) density matrix. Notably, we show that ergodicity is stable under randomizations, namely that every random mixture o...
متن کاملCategories of quantum and classical channels
We introduce a construction that turns a category of pure state spaces and operators into a category of observable algebras and superoperators. For example, it turns the category of finite-dimensional Hilbert spaces into the category of finite-dimensional C*-algebras and completely positive maps. In particular, the new category contains both quantum and classical channels, providing elegant abs...
متن کاملClassical and Quantum Factors of Channels
Given a classical channel, a stochastic map from inputs to outputs, can we replace the input with a simple intermediate variable that still yields the correct conditional output distribution? We examine two cases: first, when the intermediate variable is classical; second, when the intermediate variable is quantum. We show that the quantum variable’s size is generically smaller than the classic...
متن کاملClassical feedback for quantum channels
In this paper we investigate whether the use of a noiseless, classical feedback channel will increase the capacity of a quantum discrete memoryless channel to transmit classical information. This problem has been previously analyzed by Bowen and Nagarajan [2] for the case of protocols restricted to product input states. They showed that feedback did not increase the information capacity. In thi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Physics A
سال: 2021
ISSN: ['1751-8113', '1751-8121']
DOI: https://doi.org/10.1088/1751-8121/ac13db