Sci/Tech Nanoscale heat engine exceeds the standard Carnot efficiency limit.

[tom_mai78101]

Abstract

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 by Monte Carlo simulations that demonstrate the feasibility of our proposal. For realistic trap parameters, an increase of the efficiency at maximum power of up to a factor of 4 is reached, largely exceeding the Carnot bound.

PDF paper.

 

[Narks]

what is this in layman's terms?

 

[tom_mai78101]

in quantum mechanics you have "uncertainty". you generally can't measure things beyond a certain degree of accuracy. this isn't because we don't have the tools, but a kind of fundamental limit because, at very small scales, things are more like diffuse waves than point-like particles.
however, when you do the maths, it turns out that the constraint is usually(?) on the product of two things. for a particle, for example, those are position and speed. so there's a trade-off - you can measure position more accurately if you're willing to give up on knowing the speed at all well.
quantum squeezing is all about controlling that tradeoff as closely as possible.
but how it allows you to break "laws" of thermodynamics is beyond me.