The nanoscopic engine worked just as the laws of thermodynamics say it should, the researchers reported in a paper posted online at arXiv.org. Adjusting for the tiny weight of the ion, the power was comparable to that of a car engine, Roßnagel says. “It’s quite interesting to see that you can drive heat machines with a single atom,” he says.
Despite the measureable power output of the single-ion engine, Roßnagel warns that nano-sized engines for practical use are decades away at best. Instead, the usefulness of quantum thermo-dynamics will probably happen under the hood of other technologies.
Some researchers have their eyes on the multi-billion-dollar computer chip industry. In the drive to build ever-faster computers, engineers keep shrinking transistors to pack more and more onto chips. The transistors, some just tens of nano-meters wide, tend to leak electrons and heat up. That heat ruins the energy efficiency of the computer and damages components. Quantum thermodynamics could help physicists learn tricks to reduce the amount of wasted heat or perhaps even harvest it with small devices inside the computer.
Heat management is even more crucial for physicists seeking to build practical quantum computers. Such a device needs to operate at extremely low temperatures to exploit quantum effects and potentially outperform traditional computers.
Next, Roßnagel and his colleagues plan to chill their single atom until it’s capable of maintaining delicate quantum states including superposition and entanglement. Such an experiment would put Huber’s theoretical results to the test and expose the potential of adjusting those “quantumness” knobs to better exploit heat to do work.
A few contrarians in the physics community say that such experiments could finally violate the vaunted second law of thermodynamics. But don’t bet on it. Early 20th century English astrophysicist Arthur Eddington is still looking good with his prediction that any theory attempting to defy the second law will “collapse in deepest humiliation.” But he didn’t say anything about moving the goalposts a bit.
