Researchers at the University of Florence and Istituto dei Sistemi Complessi, in Italy, have recently proved that the invasiveness of quantum measurements might not always be detrimental. In a study published in Physical Review Letters, they showed that this invasive quality can actually be exploited, using quantum measurements to fuel a cooling engine.

Michele Campisi, one of the researchers involved in the study, has been studying quantum phenomena for several years. In his recent work, he investigated whether quantum phenomena can impact the thermodynamics of nanoscopic devices, such as those employed in quantum computers.

“Most colleagues in the field were looking at coherence and entanglement while only few were looking at another at genuine quantum phenomenon, i.e., the quantum measurement process,” Campisi told Phys.org. “Those studies suggested that you need to accompany measurements with feedback control, as in Maxwell’s demon, in order to exploit their potential. I started thinking about it, and eureka—since quantum measurements are very invasive, they are accompanied by energy exchanges, hence can be used to power engines without the need to do feedback control.”

Read more

Circa 2017

---

Getting something from nothing sounds like a good deal, so for years scientists have been trying to exploit the tiny amount of energy that arises when objects are brought very close together. It’s a source of energy so obscure it was once derided as a fanciful source of “perpetual motion.” Now, a research team including Princeton scientists has found a way to harness a mysterious force of repulsion, which is one aspect of that force.

This energy, predicted seven decades ago by the Dutch scientist Hendrik Casimir, arises from quantum effects and can be seen experimentally by placing two opposing plates very close to each other in a vacuum. At close range, the plates repel each other, which could be useful to certain technologies. Until recently, however, harnessing this “Casimir force” to do anything useful seemed impossible.

A new silicon chip built by researchers at Hong Kong University of Science and Technology and Princeton University is a step toward harnessing the Casimir force. Using a clever assembly of micron-sized shapes etched into the plates, the researchers demonstrated that the plates repel as they are brought close together. Constructing this device entirely out of a single silicon chip could open the way to using the Casimir force for practical applications such as keeping tiny machine parts from sticking to each other. The work was published in the February issue of the journal Nature Photonics.

Read more