Presented by:
Srikant Raut
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Introduction to the topic
• With the advancement of technology and complexity of computers, the need for massive storage is mandatory.
• Hard disks continue to shrink in size, gain increased storage capacity and increased transfer speeds.
• As storage density of hard disk is increasing at rate of 60% per year and is approaching its atomic level saturation, there is a need for adapting some other technique to make maximum utilization of the available space.
DISADVANTAGES
• The hard disks don’t make complete utilization of the properties of magnetic materials.
• Efficiency remains comparatively low.
• The memory field in a hard disk does not flow in all directions.
• Question mark to the future extendibility of magnetic storage.
DOMAIN THEORY
• This theory was put forth to explain the nature of the magnetic substances and the concept behind their inherent magnetic properties.
• The reason is attributed to the spin exchange interaction of atoms in those materials.
• Their magnetization can be influenced by the application of very low magnetic fields.
Effect of External field
• When a weak external magnetic field is applied over a ferromagnetic substance, the domain in the direction of the external field expands at the cost of other domains.
• When a strong external magnetic field is applied, the domains adjust such that all the domains reorient themselves in the direction of the external field.
Proposed Technology
• The effect of a strong external field can be made use of to produce many states by giving the read/write head, the capability to orient the bit fields in various directions.
• This implies that 3 binary digits can represented by a single bit field .
• Thrice the amount of information stored in a normal hard disk can be stored in the same by using this new technology.
Technical feasibility
• Writing
• To perform writing, a decoder is used as the switching circuit. The inputs are in binary form.
• Hence they should be converted into the required numbering system.
• The decoder establishes a connection to the required strip.
• When any strip is magnetized it will make the bit field present beneath it to be oriented towards the direction of the strip
• Reading
• The same head can be used for reading.
• The strip is made to pass over the particular bit field and the induced current is measured.
• An encoder is used to get the binary value.
Conclusion
As the world enters an abrupt computerization phase, the need for larger storage has become the need of the hour. The hard disks are approaching their near saturation. The proposed technology can change the future of hard disks.