Capacitive crossbar arrays

1. A capacitive crossbar array comprises:

a first set of conductors;

a second set of conductors, the first set of conductors intersecting the second set of conductors to form crosspoints;

a nonlinear capacitive device interposed between a first conductor within the first set and a second conductor within the second set at a crosspoint; the nonlinear capacitive device being configured to store information which is accessible through said first conductor and said second conductor.

2. The array according to claim 1 , in which each conductor in the first set of conductors intersects all of the conductors in the second set of conductors to form crosspoints, a nonlinear capacitive device being formed at each crosspoint.

3. The array according to claim 1 , in which the information is encoded into the nonlinear capacitive device as a high capacitance or a low capacitance state, the high capacitance state having greater capacitive nonlinearity than the low capacitance state.

4. The array according to claim 1 , further comprising a reading voltage pulse train, the reading voltage pulse train having a characteristic voltage of V R and a frequency defined by:

1/( R*C j ( V R ))≦ f≦ 1/( R*N*C j ( V R /2))

where R is the resistance of conductors in the cross bar array; C j =the capacitance of nonlinear capacitive devices in the capacitive crossbar array as a function of the characteristic voltage V R ; N is a number of semi-selected devices; and f is a frequency of the reading voltage pulse train.

5. The array according to claim 1 , in which the nonlinear capacitive device is a solid state nonlinear capacitor having a depletion region which exhibits nonlinear capacitance as a function of an applied reading voltage.

6. The array according to claim 5 , in which the solid state nonlinear capacitor is a memcapacitor comprising a memcapacitive matrix and mobile dopants.

7. The array according to claim 6 , in which the memcapacitor further comprises a Schottky barrier at an interface between the memcapacitive matrix and one of the first conductor and second conductor, the Schottky barrier exhibiting nonlinear capacitance as a function of the applied reading voltage.

8. The array according to claim 6 , in which a programming voltage applied to alter the state of the memcapacitor exceeds the breakdown voltage for the Schottky barrier.

9. The array according to claim 1 , further comprising semi-selected capacitive devices, the nonlinear capacitive device being configured such that the lumped capacitance of the semi-selected devices at a first reading voltage is less than the capacitance of the selected device at a second reading voltage.

10. The array according to claim 9 , in which the first reading voltage has approximately one half the magnitude of the second reading voltage.

11. A method for utilizing a capacitive crossbar array comprises:

applying a programming voltage across a nonlinear capacitive device, the nonlinear capacitive device being interposed between an upper wire and a lower wire of the capacitive crossbar array;

altering a capacitive state of the nonlinear capacitive device;

removing the programming voltage, the capacitive state of the nonlinear capacitive device remaining substantially stable until another programming voltage is applied;

applying a reading voltage; and

detecting the capacitive state of the nonlinear capacitive device.

12. The method according to claim 11 , in which the nonlinear capacitive device is a memcapacitor, the programming voltage exceeding a breakdown voltage of the memcapacitor such that electrical current flows through the memcapacitor, thereby increasing the mobility of mobile dopants within the memcapacitor.

13. The method according to claim 11 , in which applying the programming voltage further comprises:

dividing the programming voltage into two sub-voltages;

applying one of the sub-voltages to the upper wire; and

applying the other sub-voltage to the lower wire such that the nonlinear capacitive device is subject to the sum of the sub-voltages.

14. The method of claim 11 , in which applying the reading voltage comprises:

applying a voltage pulse train to one of the upper wire and lower wire; and detecting the transmission of the voltage pulse train through the nonlinear capacitive device to the other wire.