Research Institute of Electrical Communication Tohoku University


Hiroaki Muraoka,Professor

Simon J. Greaves,Associate Professor

H.Muraoka S.J.Greaves

Research Activities

Our main interest lies in high-density information storage technology. The core technology is magnetic recording with fast data transfer and large storage capacity, which is applied in hard disk drives and magnetic tape storage. Recently, multi-media information, such as digital movies and music, that requires very large storage capacities is used in broad applications from internet to mobile communication. This trend accelerates the areal density increase of magnetic recording. Recording theories, devices, and systems based on perpendicular recording are being studied in order to attain ultra-high density information storage. Our target is terabit storage (over 5 Tbits/inch2 areal density), in which the bit size corresponds to an area of 10 nm by 10 nm.

Laboratory Web Page

Information Storage Systems (Prof. Muraoka)

Single-pole heads and perpendicular disks are investigated through read/write experiments, as shown in Fig. 1, to improve the recording performance. For extremely large capacity storage systems, storage grids working on a network, as shown in Fig. 2, are also explored.

Research topics

  • High areal density hard disk drives
  • Head/disk devices for high density magnetic storage
  • Digital signal processing for high density storage
  • Network storage for large capacity file server

Recording Theory Computation(Assoc. Prof. Greaves)

A computer simulation utilizing micromagnetics is being carried out to obtain design guidelines for ultra-high density recording.

Research topics

  • Micromagnetic simulation for high density read/write theory

Fig. 1 Read/write measurement using a single-pole head and a perpendicular medium.
Fig. 2 A large-scale storage system with parallel HDD operation.