The controlled rotation of entanglement in altermagnets

TL;DR

This paper investigates how scattering in altermagnetic systems can be used to control and generate entanglement between electrons, with potential applications in quantum information processing.

Contribution

It demonstrates controlled rotation of entanglement via spin-orbit coupling and shows how external magnetic fields can tailor entangled states in altermagnets.

Findings

Achieved over 70% fidelity with Bell states.

Controlled entanglement rotation via spin-orbit coupling.

Tuning magnetic fields influences entanglement properties.

Abstract

Altermagnetism became very popular because of unique features, namely coupling between magnetic properties and momentum of itinerant electrons. The particular model of the altermagnetic system of our interest has already been studied in recent publications in a different context: Phys. Rev. B \textbf{108}, L140408 (2023). Here, we study the scattering process of an itinerant electron from the altermagnetic system on the electron localized in a quantum dot. We found a spatially inhomogeneous distribution of quantum entanglement in the post-scattering state. An interesting observation is the controlled rotation of entanglement achieved by means of spin-orbital coupling constant in altermagnetic. We also studied Reny entropy and the effect of disorder in the system leading to randomness in the spin-orbit constant. Our main finding is that due to the unique properties of an altermagnetic system, tuning the applied external magnetic field allows tailoring of the desired entangled state. Thus, the scattering process, in essence, mimics the Hadamard-CNOT Gate transformation, converting the initial disentangled state into the entangled state of Bell's state. In particular, we achieved more than 70 percent fidelity between the post-scattering and Bell's states.