Semiconductors of the future may be cooled by lasers, quantum physics

Semiconductors of the future may be cooled by lasers, quantum physics


A team of scientists have announced a successful experiment cooling semiconductors through the use of quantum physics and nano physics.

Researchers at the Niels Bohr Institute have combined two worlds of quantum physics and nano physics, leading to the discovery of a new method for laser cooling semiconductor membranes.

“In experiments, we have succeeded in achieving a new and efficient cooling of a solid material by using lasers. We have produced a semiconductor membrane with a thickness of 160 nanometers and an unprecedented surface area of 1 by 1 millimeter,” said Koji Usami, associate professor at Quantop at the Niels Bohr Institute. “In the experiments, we let the membrane interact with the laser light in such a way that its mechanical movements affected the light that hit it.”

using lasers, researchers sought to direct the light to strike the semiconductor membrane. Once it struck the outer membrane, the light was reflected via a mirror, a process repeated several times over. Some of the light is absorbed by the membrane, which heats up the membrane, causing expansion.

The team noted that the latest batch of experiments may lead to the semiconductors of the future. Cooling technology is increasingly important as low-power consumption is now the biggest priority in the design of new chips, particularly for mobile devices such as smartphones, tablets and other portable gadgets that are increasingly relying on the technology.

“Efficient cooling of mechanical fluctuations of semiconducting nanomembranes by means of light could also lead to the development of new sensors for electric current and mechanical forces… Such cooling in some cases could replace expensive cryogenic cooling, which is used today and could result in extremely sensitive sensors that are only limited by quantum fluctuations,” said researchers.

The paradox is that even though the membrane as a whole is getting a little bit warmer, the membrane is cooled at a certain oscillation and the cooling can be controlled with laser light, said scientists.

The laser cooling of atoms have been practiced for many years, however, researchers working on the current project have cooled the semiconductor down to near absolute zero, minus 273 degrees C, using focused lasers and a kind of link — partly by relying on quantum mechanics. Using quantum optical techniques, they have measured the quantum fluctuations of the atomic spin.

This latest development is an examination of how far the limits of quantum mechanics can be applied to macroscopic materials. For the researchers, the latest research may results in new possibilities in optomechanics, which is the interaction between light and a mechanical motion.

The study has been published in the scientific journal, Nature Physics.