The quantum information processing research group of the binding system of the Institute of Precision Measurement Science and Technology Innovation of the Chinese Academy of Sciences, in cooperation with the Guangzhou Institute of Industrial Technology and others, based on the ultra cold 40Ca+ion experimental platform, experimentally explored the impact of entanglement as a quantum resource on the quantum engine. The experimental results show that quantum engines can output more useful work when their working material is in an entangled state, indicating that entanglement can be used as fuel.

Entanglement in information processing is a unique quantum resource that can accelerate computation speed, ensure information security in communication, and improve measurement accuracy. Currently, it is not entirely clear whether entanglement can play a role in energy conversion and utilization; There is no consensus on whether quantum engines with entanglement properties are superior to classical engines and under what conditions they occur. At the same time, there are few experimental studies on quantum engines using quantum entangled systems as working materials, and there is also no quantitative experimental verification.

The research group designed a quantum engine with entanglement properties using ultracold 40Ca+ions stably bound in ion traps as working materials. This quantum engine comes with a quantum payload. It is acted upon by a quantum vibrational mode shared by ions. Researchers use thermodynamic cycles to convert the photon energy of lasers into phonon energy of quantum loads through working substances (ions) using the quantum engine, and define the conversion efficiency. Furthermore, in order to estimate how much of the converted energy can be extracted as useful work, researchers defined mechanical efficiency.

To verify the role of entanglement in quantum engines, this study quantitatively evaluated the performance of quantum engines by adjusting the entanglement degree of working materials. In the experiment, it was studied to control the time of entanglement logic gate operation by precisely manipulating the laser, in order to obtain working materials with different entanglement degrees. At the same time, the study obtained the conversion efficiency and mechanical efficiency under different entanglement levels by measuring the number of photons absorbed in the working material and the increase in the number of phonons in the load. Experiments have shown that the maximum mechanical efficiency occurs at the point where the working material has the maximum entanglement, but the conversion efficiency is almost unaffected by the entanglement degree. Experimental data analysis shows that quantum engines can output more useful work when their working material is in an entangled state; The conversion efficiency of quantum engines is independent of entanglement and also independent of the output of useful work.

This achievement provides experimental evidence that entanglement can serve as a fuel in quantum engines and suggests that the development of quantum engines should focus more on mechanical efficiency rather than conversion efficiency. The above achievements provide a new perspective for the development of micro energy devices such as quantum motors and quantum batteries.



Recently, the research findings related to Energy Conversion Device Using a Quantum Engine with the Work Medium of Two Atom Entanglement were published in the Physical Review Letters. The research work has received support from the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.



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