Negative correlations can play a positive role in disordered quantum walks

TL;DR

This paper explores how negative correlations in disordered quantum walks can enhance quantum entanglement, revealing that such correlations have a more significant impact than previously thought.

Contribution

It demonstrates that negative correlations in temporal disorder can increase entanglement entropy in quantum walks, challenging prior assumptions about disorder effects.

Findings

Negative correlation leads to higher entanglement entropy.

Weak disorder with negative correlation enhances quantum entanglement.

Counter-intuitive role of negative correlations in quantum walks.

Abstract

We investigate the emerging properties of quantum walks with temporal disorder engineered from a binary Markov chain with tailored correlation, $C$, and disorder strength, $r$. We show that when the disorder is weak -- $r \ll 1$ -- the introduction of negative correlation leads to a counter-intuitive higher production of spin-lattice entanglement entropy, $S_e$, than the setting with positive correlation, that is $S_e(-|C|)>S_e(|C|)$. These results show that negatively correlated disorder plays a more important role in quantum entanglement than it has been assumed in the literature.