Magnetic recording medium and magnetic memory apparatus

A patterned magnetic recording medium in which pillar-like nanostructures each comprising a multilayered film showing a tunneling magnetoresistance effect or a multilayered film showing a giant magnetoresistance effect are surrounded by insulators in such a way as to be laid out apart from one another at substantially even pitches and are provided on a conductive electrode layer formed on a substrate.

A patterned magnetic recording medium in which pillar-like nanostructures each comprising a multilayered film having a lamination of a multilayered film showing a tunneling magnetoresistance effect and a multilayered film showing a giant magnetoresistance effect are surrounded by insulators in such a way as to be laid out apart from one another at substantially even pitches and are provided on a conductive electrode layer formed on a substrate.

A magnetic memory apparatus comprising:

• a patterned magnetic recording medium in which nanostructures each comprising a multilayered film showing a tunneling magnetoresistance effect and/or a multilayered film showing a giant magnetoresistance effect are surrounded by insulators in such a way as to be laid out apart from one another at substantially even pitches and are provided on a conductive electrode layer formed on a substrate;
• and
• a cantilever array in which cantilevers having conductive chips at distal ends are laid out in an array and apart from one another in such a way as to be associated with said nanostructures, whereby information is written or read by a current supplied from that one of said conductive chips which is associated with a desired one of said nanostructures as that conductive chip is put in contact with said desired nanostructure.

A magnetic recording method which uses a patterned magnetic recording medium in which nanostructures each comprising a multilayered film showing a tunneling magnetoresistance effect and/or a multilayered film showing a giant magnetoresistance effect are surrounded by insulators in such a way as to be laid out apart from one another at substantially even pitches and are provided on a conductive electrode layer formed on a substrate, and a cantilever array in which cantilevers having conductive chips at distal ends are laid out in an array and apart from one another in such a way as to be associated with said nanostructures, and writes digital information by inverting magnetization with 1 being a state where a resistance of said multilayered film is high while 0 is a state where said resistance is low, using a current supplied from that one of said conductive chips which is associated with a predetermined one of said nanostructures as that conductive chip is put in contact with said predetermined nanostructure.

A signal reading method which uses a patterned magnetic recording medium in which nanostructures each comprising a multilayered film showing a tunneling magnetoresistance effect and/or a multilayered film showing a giant magnetoresistance effect are surrounded by insulators in such a way as to be laid out apart from one another at substantially even pitches and are provided on a conductive electrode layer formed on a substrate, and a cantilever array in which cantilevers having conductive chips at distal ends are laid out in an array and apart from one another in such a way as to be associated with said nanostructures, and detects a level of a resistance of each multilayered pillar by putting that one of said conductive chips which is associated with a predetermined one of said nanostructures in contact with said predetermined nanostructure and causing a current whose value is smaller than that of a current by which magnetization of said multilayered film is inverted to flow from said conductive chip.