# Quasiperiodic magnetic chain as a spin filter for arbitrary spin states

## TL;DR

This paper proposes a quasiperiodic magnetic chain system that can act as a spin filter for particles with any spin, by tuning magnetic and potential parameters, with potential applications in spintronics.

## Contribution

It introduces a novel quasiperiodic magnetic chain model capable of filtering arbitrary spin states through tunable correlations, expanding spintronic device design possibilities.

## Key findings

- Achieves complete spin filtering for arbitrary spin states.
- Demonstrates tunability via external gate voltage.
- Potential for experimental realization with ultracold gases.

## Abstract

We show that a quasiperiodic magnetic chain comprising magnetic atomic sites sequenced in Fibonacci pattern can act as a prospective candidate for spin filters for particles with arbitrary spin states. This can be achieved by tuning a suitable correlation between the amplitude of the substrate magnetic field and the on-site potential of the magnetic sites, which can be controlled by an external gate voltage. Such correlation leads to a spin filtering effect in the system, allowing one of the spin components to completely pass through the system while blocking the others over the allowed range of energies. The underlying mechanism behind this phenomena holds true for particles with any arbitrary spin states S = 1, 3/2, 2, . . ., in addition to the canonical case of spin-half particles. Our results open up the interesting possibility of designing a spin demultiplexer using a simple quasiperiodic magnetic chain system. Experimental realization of this theoretical study might be possible by using ultracold quantum gases, and can be useful in engineering new spintronic devices.