Method of improving sensitivity of electric field sensor, storage apparatus including electric field sensor, and method of reproducing information of the storage apparatus
View Patent ↗A storage apparatus includes a ferroelectric recording medium, an electric field sensor including a source region, a drain region and a resistance region electrically connecting the source region to the drain region and having a resistance, which varies according to an intensity of an electric field due to a polarization voltage of an electric domain of the recording medium, a voltage applying unit applying a drain voltage between the source region and the drain region, and a reproducing signal detection unit including at least one negative resistor installed in an electric circuit connecting the drain region to the voltage applying unit, and detecting a change in a voltage between the drain region and the at least one negative resistor.
1. A method of improving the sensitivity of an electric held sensor comprising a source region, a drain region and a resistance region electrically connecting the source region to the drain region and having a resistance, which varies according to an intensity of an electric field, and detecting a change in the electric field by measuring a change in a drain current flowing through the resistance region, the measuring the change in the drain current comprises:
passing the drain current through at least one negative resistor; and
detecting a change in a voltage between the drain region and the at least one negative resistor.
2. The method of claim 1 , further comprising utilizing a tunnel diode as the at least one negative resistor.
3. The method of claim 1 , further comprising utilizing a plurality of tunnel diodes, which are connected in series and/or parallel, as negative resistors.
4. The method of claim 3 , wherein the plurality of tunnel diodes are connected in series and/or in parallel so that a negative resistance region of a load line of the tunnel diodes has a similar gradient to a gradient of a linear region of a curve of drain current with respect to a drain voltage of the electric field sensor, and the negative resistance region and the linear region cross each other.
5. A storage apparatus comprising:
a ferroelectric recording medium;
an electric field sensor including a source region, a drain region and a resistance region, which electrically connects the source region to the drain region and has a resistance which varies according to intensity of an electric field due to a polarization voltage of an electric domain of the ferroelectric recording medium;
a voltage applying unit applying a drain voltage between the source region and the drain region; and
a reproducing signal detection unit including at least one negative resistor installed in an electric circuit connecting the drain region to the voltage applying unit, and detecting a change in a voltage between the drain region and the at least one negative resistor.
6. The storage apparatus of claim 5 , wherein the negative resistor is a tunnel diode.
7. The storage apparatus of claim 6 , wherein the reproducing signal detection unit comprises a plurality of tunnel diodes connected in series and/or in parallel.
8. The storage apparatus of claim 7 , wherein the tunnel diodes are connected in series and/or in parallel so that a negative resistance region of a load line of the tunnel diodes has a similar gradient to a gradient of a linear region of a curve of drain current with respect to the drain voltage of the electric field sensor, and the negative resistance region and the linear region cross each other.
9. The storage apparatus of claim 5 , wherein the electric field sensor further comprises a writing electrode which is disposed on the resistance region, and to which a voltage, of which the absolute value is equal to or greater than a threshold voltage, is applied to record information on the ferroelectric recording medium, and wherein an insulating layer is disposed between the writing electrode and the resistance region.
10. A method of reproducing information of a storage apparatus, the storage apparatus comprising: a ferroelectric recording medium; an electric field sensor including a source region, a drain region and a resistance region electrically connecting the source region to the drain region and having a resistance, which varies according to an intensity of an electric field due to a polarization voltage of an electric domain of the recording medium; and a voltage applying unit applying a drain voltage between the source region and the drain region, wherein the method comprises:
installing at least one negative resistor in an electric circuit connecting the drain region to the voltage applying unit to pass an output current of the electric field sensor through the at least one negative resistor; and
detecting a change in a voltage between the drain region and the at least one negative resistor to obtain a reproducing signal.
11. The method of claim 10 , wherein a plurality of tunnel diodes, which are connected in series and/or parallel, are used as negative resistors.
12. The method of claim 11 , wherein the tunnel diodes are connected in series and/or in parallel so that a negative resistance region of a load line of the tunnel diodes has a similar gradient to a gradient of a linear region of a curve of drain current with respect to the drain voltage of the electric field sensor, and the negative resistance region and the linear region cross each other.