Chinese scientists have reached a new threshold by harnessing the capability of quantum inseparability as fuel for quantum engines, potentially revolutionizing energy efficiency and powering future quantum technologies.
The phenomenon of inseparability keeps two separate photons tightly bound, apparently communicating faster than light, regardless of the distance between them.
Researchers from the Innovation Academy for Precision Measurement Science and Technology of the Chinese Academy of Sciences pointed out that the discovery demonstrates the potential to use quantum inseparability as fuel for quantum engines.
According to Zhou Fei, one of the corresponding authors, the highlight of the study is “the first experimental realization of a quantum engine with inseparability characteristics, which quantitatively verified that inseparability can serve as ‘fuel’.”
How is inseparability used as fuel for quantum engines?
In the study, published in the journal Physical Review Letters, Zhou, along with co-author Feng Mang and their team, demonstrated that the inseparability phenomenon improves the output efficiency of quantum engines.
Unlike conventional engines, which rely on thermal combustion, a quantum engine uses lasers to move particles between quantum states, converting light into kinetic energy.
Thus, Zhou’s team used ultracold 40Ca+ ions held in an ion trap as the working material for the quantum engine. They devised a thermodynamic process that converts external laser energy into ion vibrational energy.
“We chose the inseparability states of two spinning ions as the working substance, their vibrational modes acting as the charge. By precise adjustments of the laser frequency, amplitude and duration, the ions were transferred from their pure initial states to states of high inseparability,” Zhou clarified.
As he points out, these measurements give the team insight into how efficiently the engine is operating and how efficiently it’s using the energy it produces.
What are quantum engines used for?
Analysis of more than 10,000 experiments indicated that increased levels of ion inseparability were correlated with improved mechanical efficiency, while conversion efficiency remained relatively unaffected by the degree of inseparability. This suggests that quantum entanglement acts as a “fuel” in quantum engines, despite its mechanism being mysterious to physicists.
“Quantum engines are currently a very active research field, with many theoretical analyzes and studies, but very few experimental results are provided,” Zhou noted.
According to Zhou, the findings of the study open up new perspectives for the development of micro-energy devices such as quantum motors and batteries. They suggest that the nonseparability properties of the work material can enhance the maximum energy that can be extracted.
While quantum batteries may not store as much energy as those in electric vehicles, their real advantage lies in their ability to power extended quantum computers and circuits. Thus, the future challenge is to increase the variety of materials while maintaining the quality of inseparability, leading to higher production.