Japanese researchers have discovered a way to overcome long-standing thermodynamic limits, such as the Carnot efficiency, by using quantum states that do not undergo thermalization. Their innovative method employs a non-thermal Tomonaga-Luttinger liquid to transform waste heat into electrical energy with greater efficiency than conventional systems. This advancement could lead to more energy-efficient electronics and future progress in quantum computing.

Energy harvesters are devices that collect power from surrounding environmental sources, offering a means to improve the efficiency of modern electronics and industrial operations. Waste heat is produced continuously by everyday technologies, including computers, smartphones, and factory machinery, as well as by large-scale systems like power plants. Energy-harvesting techniques make it possible to reclaim this otherwise lost heat and convert it into usable electricity, reducing dependence on traditional energy supplies.

Traditional energy-harvesting technologies, however, remain limited by the fundamental principles of thermodynamics. Systems that operate under thermal equilibrium face strict boundaries on how much heat can be turned into electrical power. The ratio between generated electricity and the heat drawn from a waste source is defined by the Carnot efficiency. Additional constraints, such as the Curzon-Ahlborn efficiency (which represents the efficiency achievable at maximum power output), have further restricted how much practical energy can be recovered from waste heat.

Now, a research team led by Professor Toshimasa Fujisawa from the Department of Physics at Institute of Science Tokyo (Science Tokyo), Japan, in collaboration with Senior Distinguished Researcher Koji Muraki from NTT Basic Research Laboratories, Japan, has found a way to bypass this barrier. In their paper published in Communications Physics on September 30, 2025, the team introduced a novel energy-harvesting technique that uses unique quantum states to achieve efficiencies that go beyond the conventional thermodynamic limits.