Seagate this week unveiled the industry's first hard disk drive platform that uses heat-assisted media recording (HAMR). Tom's Hardware:

The new Mozaic 3+ platform relies on several all-new technologies, including new media, new write and read heads, and a brand-new controller. The platform will be used for Seagate's upcoming Exos hard drives for cloud datacenters with a 30TB capacity and higher. Heat-assisted magnetic recording is meant to radically increase areal recording density of magnetic media by making writes while the recording region is briefly heated to a point where its magnetic coercivity drops significantly.

Seagate's Mozaic 3+ uses 10 glass disks with a magnetic layer consisting of an iron-platinum superlattice structure that ensures both longevity and smaller media grain size compared to typical HDD platters. To record the media, the platform uses a plasmonic writer sub-system with a vertically integrated nanophotonic laser that heats the media before writing. Because individual grains are so small with the new media, their individual magnetic signatures are lower, whereas magnetic inter-track interference (ITI) effect is somewhat higher. As a result, Seagate had to introduce its new Gen 7 Spintronic Reader, which features the "world's smallest and most sensitive magnetic field reading sensors," according to the company. Because Seagate's new Mozaic 3+ platform deals with new media with a very small grain size, an all-new writer, and a reader that features multiple tiny magnetic field readers, it also requires a lot of compute horsepower to orchestrate the drive's work. Therefore, Seagate has equipped with Mozaic 3+ platform with an all-new controller made on a 12nm fabrication process.

Abstract credit: https://hardware.slashdot.org/story/24/01/19/1149214/30tb-hard-drives-are-nearly-here