1. A device comprising: a nano-scale oscillator that exhibits chaotic oscillation responsive to a control input to the nano-scale oscillator, the control input including a tunable input parameter, wherein the tunable input parameter comprises a tunable input voltage, and wherein the nano-scale oscillator exhibits a plurality of negative differential response regimes within a same range of positive values of the tunable input voltage, a first negative differential response regime of the plurality of negative differential response regimes comprising a first range of currents, and a second negative differential response regime of the plurality of negative differential response regimes comprising a second range of currents different from the first range of currents, the second negative differential response regime comprising negative differential response portions that form a hysteresis loop.