Hard disk drive read/write head

The second contribution spans an even larger range of length and times scales. Two benchmark examples illustrate the design approach polymer electrolyte fuel cells and hard disk drive (HDD) systems. In the current HDDs, the read/write head flies about 6.5 nm above the surface via the air bearing design. Multi-scale modeling tools include quantum mechanical (i.e., density functional theory (DFT)), atomistic (i.e., Monte Carlo (MC) and molecular dynamics (MD)), mesoscopic (i.e., dissipative particle dynamics (DPD) and lattice Boltzmann method (LBM)), and macroscopic (i.e., LBM, computational fluid mechanics, and system optimization) levels. 

Han, G. C., et al. A Differential Dual Spin Valve with High Pinning Stability. Applied Physics Letters 96 (2010). Discusses how hard disk drives could include ten terabytes of data per square inch using a new read-write head design. 

Figure 20.23 Schematic diagram of a hard disk drive that uses the perpendicular magnetic recording medium also shown are inductive write and magnetoresistive read heads.

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