Mechanisms of heat transport across a nano-scale gap in heat assisted magnetic recording

Abstract

This paper compares different mechanisms of heat transport across nano-scale gaps and discusses the role of electromagnetic phenomena in heat transport in general nano-scale layered structures. The results of the analysis suggest that heat transfer across sub-5 nm gaps like that appearing in prototypes of heat assisted magnetic recording (HAMR) systems is dominated by direct intermolecular interactions between the separated bodies and is little affected by electromagnetic radiation. The analysis further suggests that local heating for HAMR with sub-5 nm spacing can be more efficiently achieved by a Joule heater that is simpler to fabricate than laser-based optical systems and is less destructive for the nano-scale transducers than laser radiation, which may lead to their structural damage and short duration life of nanoscale transducers.

Thermal Effect of the Back Radiation from Disk to Head after Laser Heating in HAMR

“…Research on the nearfield heat transfer is concentrated on the theory of heat transport by phonon tunneling, see Refs. [11][12][13]. In recent years [14], the theoretical and experimental studies on the near-field radiative heat transfer have obviously increased.…”