# A Spiral Spin State with Open Boundary Conditions in a Magnetic Field

## TL;DR

This paper models a spiral spin state in a thin film using a classical Heisenberg model with open boundaries, analyzing how magnetic fields influence the transition to ferromagnetism and explaining susceptibility jumps.

## Contribution

It provides numerical analysis of spiral states with open boundary conditions, confirming analytic results and elucidating magnetic susceptibility behavior in thin films.

## Key findings

- Critical magnetic field increases with film thickness.
- Spiral states transition to ferromagnetic states at a critical field.
- Numerical results align with continuum analytic predictions.

## Abstract

In order to model a spiral spin state in a thin film, we study a classical Heisenberg model with open boundary conditions. With magnetic field applied in the plane of the film, the spin state becomes ferromagnetic above a critical field that increases with thickness $N$. For a given $N$, the spiral passes through states with $n= n_0$ up to 0 complete periods in steps of 1. These numerical results agree with earlier analytic results in the continuum limit and help explain the susceptibility jumps observed in thin films.