Patent ID: 8427773
Filing Date: 2013-04-23
Classification: G11B

Abstract:
1. A method for magnetic recording using a magnetic recording head to a recording layer of a magnetic recording medium arranged to oppose the magnetic recording head, the magnetic recording head including a main pole, an auxiliary pole, a main coil for generating a perpendicular recording magnetic field to the main pole, and either a sub-coil for generating an in-plane alternate current magnetic field of a microwave band to the main pole or a microwave radiator that is arranged in vicinity of the main pole and that radiates microwaves, the method comprising: a step for modulating an amplitude of the in-plane alternate current magnetic field by modulating an amplitude of microwave alternating current that is applied to either the sub-coil or the microwave radiator using a modulation signal wave so that a ratio (fc/fm) of a carrier frequency (fc) to a modulation frequency (fm) is from 10 to 40; and a step for performing magnetic recording to the recording layer of the magnetic recording medium by applying the perpendicular recording magnetic field while applying the in-plane alternate current magnetic field with the modulated amplitude to the magnetic recording medium.