Scientists have designed a theoretical engine where the 'piston' is a stable wave of energy that never loses its shape.
April 14, 2026
Original Paper
Spectral thermodynamics of a soliton heat engine
arXiv · 2604.09831
The Takeaway
By using a 'soliton'—a ripple that moves without decaying—as the working substance, this engine can convert heat into energy more efficiently than standard quantum motors. It treats a stable wave as a physical fuel that can be engineered for maximum power output.
From the abstract
We demonstrate a thermodynamic engine whose working substance is a sine-Gordon soliton in a heterogeneous current-driven Josephson junction. We show that solitons can act as thermodynamic working substances whose internal spectral structure enables energy conversion beyond conventional few-level engines. By dynamically deforming the soliton using a controllable dipole current, the internal bound-state spectrum of the soliton can be engineered in time, enabling a finite-time Carnot-like cycle bas