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nanotimes News in Brief


12-01 :: January 2012


Aluminium nanowire, whose vibrations are coupled to the superconducting cavity (on the right), enabling almost noise- less amplification of microwaves. © Aalto University, Finland


Physicists in Aalto University, Finland, have shown how a nanomechanical oscillator can be used for detection and amplification of feeble radio waves or microwaves. A measurement using such a tiny device, resembling a miniaturized guitar string, can be performed with the least possible disturbance. The researchers cooled the nanomechanical oscil- lator, thousand times thinner than a human hair, down to a low temperature near the absolute zero at -273° C (-459.4° F). Under such extreme condi- tions, even nearly macroscopic sized objects follow the laws of quantum physics which often contradict common sense. In the Low Temperature Laboratory experiments, the nearly billion atoms comprising the nanomechanical resonator were oscillating in pace in their shared quantum state.


The scientists had fabricated the device in contact with a superconducting cavity resonator, which ex-


changes energy with the nanomechanical resonator. This allowed amplification of their resonant moti- on. This is very similar to what happens in a guitar, where the string and the echo chamber resonate at the same frequency. Instead of the musician playing the guitar string, the energy source was provided by a microwave laser.


F. Massel, T. T. Heikkilä, J.-M. Pirkkalainen, S. U. Cho, H. Saloniemi, P. J. Hakonen, M. A. Sillanpää: Micro- wave amplification with nanomechanical resonators, In: Nature, Vol. 480(2011), Issue 7377, Pages 351-354 December 15, 2011, DOI:10.1038/nature10628: http://dx.doi.org/10.1038/nature10628


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