Volatile capacitance of resistor with differential resistance

The differential current dV/dR in a resistor forms a volatile capacitance across itself. When the differential current is less than the Ohm current, V/R⁠, the volatile capacitance is positive. Conversely, when it exceeds the Ohm current, the volatile capacitance becomes negative. If the differential current equals the Ohm current, the volatile capacitance is zero. The transition of this volatile capacitance from positive to negative has been observed in a combination of multi-walled carbon nanotube material and vacuum space. Additionally, we have fabricated a two-dimensional planar inductor without a coil using this negative capacitor.