Physicists generate electrical currents from noise – Physics World
Connect the dots: the energy-harvesting device Two quantum dots have been used to generate an electrical current from voltage noise. However, team member Fabian Hartmann explains that it shows that small voltage fluctuations can drive a current: “A device derived from our sample might be able to provide the necessary power to drive autonomous and self-powered systems.” Coupled quantum dots The experiment comprises two quantum dots, which are discs of semiconductor about 300 nm in diameter. The researchers then connected three conducting leads to the system: two to the upper quantum dot to allow current to flow across the dot and one linking the lower quantum dot to a voltage source (several volts) with superimposed noise in the millivolt range. While increasing the intensity of the noise applied to the lower quantum dot, the researchers measured larger currents across the upper quantum dot. In addition, further work is needed to show that currents can be driven by thermal fluctuations rather than voltage noise.