Abstract: A high-sensitivity field effect transistor using as a channel ultrafine fiber elements such as carbon nanotube, and a biosensor using it. The field effect transistor comprises a substrate, a source electrode and a drain electrode arranged on the substrate, a channel for electrically connecting the source electrode with the drain electrode, and a gate electrode causing polarization due to the movement of free electrons in the substrate. For example, the substrate has a support substrate consisting of semiconductor or metal, a first insulating film formed on a first surface of the support substrate, and a second insulating film formed on a second surface of the support substrate, the source electrode, the drain electrode, and the channel arranged on the first insulating film, the gate electrode disposed on the second insulating film.

Abstract: A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

Abstract: A magnetic recording element is composed of a first magnetic film to generate spin vortex by an external magnetic field and a second magnetic film having a magnetization perpendicular to the surfaces thereof, and also an insulating layer to control (repress) a current through the magnetic recording element which is formed between the first magnetic film and the second magnetic film. A given external magnetic field is applied to the magnetic recording element, to generate a spin vortex in the first magnetic film and then, generate a vertical magnetization at the center of the spin vortex. Then, a given data is written on the vertical magnetization.

Abstract: A scanning magnetism detector includes a probe made of a solid material formed of a single crystal having spin polarization and electrical conductivity properties. When the probe is brought into proximity with a magnetic substance, a surface condition of the magnetic substance can be detected by measuring tunnel current flow between the probe and the surface of the magnetic substance.

Abstract: A probe for measuring a leakage magnetic field includes a substrate, a flexible cantilever having one end fixed to the substrate and a free end, and at least one magneto resistive element arranged on the free end of the cantilever. The magneto resistive element has a width within a range from 10 nm to 1 &mgr;m as measured in a direction perpendicular to a longitudinal direction of the cantilever and in a direction in which the cantilever can be deflected.

Abstract: At the forefront of a probe is formed a carbon nanotube having an armchair type crystal structure or of which the forefront is chemically modified with modifying molecules.

Abstract: A ferromagnetic film, which has an inherent resonant frequency, is disposed in a cavity resonator. An electromagnetic wave, which has an input frequency equal to the resonant frequency of the ferromagnetic film, is introduced to the ferromagnetic film from an orifice of the cavity resonator to generate a ferromagnetic resonance in the ferromagnetic film, and thus, multiply the input frequency of the electromagnetic wave.

Abstract: At the forefront of a probe is formed a carbon nanotube having an armchair type crystal structure or of which the forefront is chemically modified with modifying molecules.

Abstract: To provide a magnetic recording method and apparatus which utilize a spin vortex as a recording unit and which enables high density recording, spin vortices (2) are recorded on a recording medium (1) such that the spin vortices (2) are aligned to form a recording track (3). The recording medium (1) is formed of a magnetic super-thin film, and positive and negative recorded spin vortices (2) are aligned thereon.

Abstract: A magnetic recording element is composed of a first magnetic film to generate spin vortex by an external magnetic field and a second magnetic film having a magnetization perpendicular to the surfaces thereof, and also an insulating layer to control (repress) a current through the magnetic recording element which is formed between the first magnetic film and the second magnetic film. A given external magnetic field is applied to the magnetic recording element, to generate a spin vortex in the first magnetic film and then, generate a vertical magnetization at the center of the spin vortex. Then, a given data is written on the vertical magnetization.

Abstract: A scanning magnetism detector includes a probe made of a solid material formed of a single crystal having spin polarization and electrical conductivity properties. When the probe is brought into proximity with a magnetic substance, a surface condition of the magnetic substance can be detected by measuring tunnel current flow between the probe and the surface of the magnetic substance.

Abstract: A ferromagnetic film, which has an inherent resonant frequency, is disposed in a cavity resonator. An electromagnetic wave, which has an input frequency equal to the resonant frequency of the ferromagnetic film, is introduced to the ferromagnetic film from an orifice of the cavity resonator to generate a ferromagnetic resonance in the ferromagnetic film, and thus, multiply the input frequency of the electromagnetic wave.

Abstract: A probe for measuring a leakage magnetic field includes a substrate, a flexible cantilever having one end fixed to the substrate and a free end, and at least one magneto resistive element arranged on the free end of the cantilever. The magneto resistive element has a width within a range from 10 nm to 1 &mgr;m as measured in a direction vertical to a longitudinal direction of the cantilever and also to a direction in which the cantilever can be deflected.