# A study of coherence based measure of quantumness in (non) Markovian channels

## TL;DR

This paper analyzes the quantumness of various Markovian and non-Markovian quantum noise channels using a coherence-based measure, revealing that increased non-Markovianity enhances channel quantumness.

## Contribution

It introduces a coherence-based witness for quantumness and applies it to diverse noise channels, highlighting the impact of non-Markovianity on quantumness.

## Key findings

- Non-Markovian channels show increased quantumness with higher non-Markovianity.
- The coherence-based measure effectively distinguishes quantumness across different channels.
- Non-dephasing channels like amplitude damping also exhibit quantumness influenced by non-Markovian effects.

## Abstract

We make a detailed analysis of quantumness for various quantum noise channels, both Markovian and non-Markovian. The noise channels considered include dephasing channels like random telegraph noise, non-Markovian dephasing and phase damping, as well as the non-dephasing channels such as generalized amplitude damping and Unruh channels. We make use of a recently introduced witness for quantumness based on the square $l_1$ norm of coherence. It is found that the increase in the degree of non-Markovianity increases the quantumness of the channel.