# The superior role of the Gilbert damping on the signal-to-noise ratio in heat-assisted magnetic recording

## TL;DR

This study reveals that Gilbert damping significantly influences the signal-to-noise ratio in heat-assisted magnetic recording, with higher damping constants improving SNR and overshadowing other parameters.

## Contribution

It demonstrates the dominant effect of Gilbert damping on SNR in HAMR, highlighting its importance over other material and head parameters.

## Key findings

- SNR saturates at damping constants ≥ 0.1
- Gilbert damping and bit length majorly affect SNR
- Other parameters have minor influence on SNR

## Abstract

In magnetic recording the signal-to-noise ratio (SNR) is a good indicator for the quality of written bits. However, a priori it is not clear which parameters have the strongest influence on the SNR. In this work, we investigate the role of the Gilbert damping on the SNR. Grains consisting of FePt like hard magnetic material with two different grain sizes $d_1=5\,$nm and $d_2=7\,$nm are considered and simulations of heat-assisted magnetic recording (HAMR) are performed with the atomistic simulation program VAMPIRE. The simulations display that the SNR saturates for damping constants larger or equal than 0.1. Additionally, we can show that the Gilbert damping together with the bit length have a major effect on the SNR whereas other write head and material parameters only have a minor relevance on the SNR.