Physicists rewrite 200-year-old principle to unlock atomic engines

A research team at the University of Stuttgart, led by physicists Eric Lutz and Milton Aguilar, has fundamentally challenged the 200-year-old Carnot principle, a cornerstone of thermodynamics that sets the maximum efficiency for heat engines operating between two thermal reservoirs. While the Carnot principle, formulated in 1824, applies to macroscopic engines like steam turbines, the researchers demonstrated that it does not hold at the atomic scale where quantum correlations between particles come into play. Their work shows that quantum heat engines can surpass the traditional Carnot efficiency limit by harnessing these correlations, which classical thermodynamics neglects. This breakthrough extends thermodynamic laws to account for quantum effects, revealing that atomic-scale thermal machines can convert both heat and quantum correlations into usable work, thus achieving higher efficiencies than previously thought possible. The findings open new avenues for developing ultra-efficient quantum engines and nanoscale technologies, including tiny molecular motors potentially capable of powering medical nanobots or manipulating materials at the atomic level. Published in Science Advances