Nonvolatile nanotube diodes and nonvolatile nanotube blocks and systems using same and methods of making same

A non-volatile composite nanotube switch, comprising:

• a first conductive terminal;
• a second conductive terminal;
• a composite nanotube article physically and electrically interposed between the first conductive terminal and the second conductive terminal,
• wherein at least a portion of the composite nanotube article is in electrical communication with at least a portion of the first conductive terminal and at least a portion of the second conductive terminal, and
• wherein the composite nanotube article comprises a first quantity of nanotubes and a second quantity of nanoscopic particles, a ratio of the first quantity to the second quantity being predefined, wherein the ratio of the first quantity to the second quantity is between 1 and 10;
• and
• control circuitry in electrical communication with and configured to apply electrical stimulus to at least one of the first and second conductive terminals,
• wherein the composite nanotube article is configured to switch among a plurality of electronic states in response to a corresponding plurality of electrical stimuli applied by the control circuitry to the first and second conductive terminals, and
• wherein, for each electronic state, the composite nanotube article provides an electrical pathway of a corresponding resistance between the first and second conductive terminals.

A high-density composite memory array, comprising:

• a plurality of word lines and a plurality of bit lines;
• a plurality of memory cells, each memory cell comprising:
• a first conductive terminal;
• a composite nanotube article in physical and electrical contact with the first conductive terminal, the composite nanotube article comprising a first quantity of nanotubes and a second quantity of nanoscopic particles, a ratio of the first quantity to the second quantity being predefined, wherein the ratio of the first quantity to the second quantity is between 1 and 10;
• a second conductive terminal in physical and electrical contact with the composite nanotube article and in electrical communication with a word line of the plurality of word lines;
• and
• select circuitry in electrical communication with a bit line of the plurality of bit lines and one of the first and second conductive terminals,
• wherein the composite nanotube article has a physical dimension that defines a spacing between the first and second conductive terminals such that the composite nanotube article is interposed between the first and second conducive terminals, and
• wherein a logical state of each memory cell is selectable by activation only of the bit line and the word line connected to that memory cell.