Nanoscale heat engine beyond the Carnot limit.

  title={Nanoscale heat engine beyond the Carnot limit.},
  author={J. Ro{\ss}nagel and Obinna Abah and Ferdinand Schmidt-Kaler and Kilian Singer and Eric Lutz},
  journal={Physical review letters},
  volume={112 3},
We consider a quantum Otto cycle for a time-dependent harmonic oscillator coupled to a squeezed thermal reservoir. We show that the efficiency at maximum power increases with the degree of squeezing, surpassing the standard Carnot limit and approaching unity exponentially for large squeezing parameters. We further propose an experimental scheme to implement such a model system by using a single trapped ion in a linear Paul trap with special geometry. Our analytical investigations are supported… 

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