New Work Achieves a Pure Quantum State Without the Need For Cooling (phys.org) 40
alternative_right shares a report from Phys.org: Three nano-glass spheres cling to one another. They form a tower-like cluster, similar to when you pile three scoops of ice cream on top of one another -- only much smaller. The diameter of the nano cluster is ten times smaller than that of a human hair. With the help of an optical device and laser beams, researchers at ETH Zurich have succeeded in keeping such objects almost completely motionless in levitation. This is significant when it comes to the future development of quantum sensors, which, together with quantum computers, constitute the most promising applications of quantum research.
As part of their levitation experiment, the researchers, led by adjunct professor of photonics Martin Frimmer, were able to eliminate the gravitational force acting on the glass spheres. However, the elongated nano object still trembled, similar to how the needle on a compass moves when settling into position. In the case of the nano cluster, the trembling motion was very fast but weak: the object made around one million deflections per second, each measuring only a few thousandths of a degree. This tiny rotational oscillation is a fundamental quantum motion exhibited by all objects, which physicists call zero-point fluctuation.
To date, no one has been successful in detecting these tiny movements for an object of this size as precisely as the ETH researchers have now done. They achieved this because they were able to largely eliminate all motions that originate from the field of classical physics and obscure the observation of quantum movements. The ETH researchers attribute 92% of the cluster's movements in their experiment to quantum physics and 8% to classical physics; they therefore refer to a high level of quantum purity. And the records do not stop there: The researchers accomplished all of this at room temperature. Quantum researchers usually have to cool their objects to a temperature close to absolute zero (-273 degrees Celsius) using special equipment. This was not required here. The research has been published in the journal Nature Physics.
As part of their levitation experiment, the researchers, led by adjunct professor of photonics Martin Frimmer, were able to eliminate the gravitational force acting on the glass spheres. However, the elongated nano object still trembled, similar to how the needle on a compass moves when settling into position. In the case of the nano cluster, the trembling motion was very fast but weak: the object made around one million deflections per second, each measuring only a few thousandths of a degree. This tiny rotational oscillation is a fundamental quantum motion exhibited by all objects, which physicists call zero-point fluctuation.
To date, no one has been successful in detecting these tiny movements for an object of this size as precisely as the ETH researchers have now done. They achieved this because they were able to largely eliminate all motions that originate from the field of classical physics and obscure the observation of quantum movements. The ETH researchers attribute 92% of the cluster's movements in their experiment to quantum physics and 8% to classical physics; they therefore refer to a high level of quantum purity. And the records do not stop there: The researchers accomplished all of this at room temperature. Quantum researchers usually have to cool their objects to a temperature close to absolute zero (-273 degrees Celsius) using special equipment. This was not required here. The research has been published in the journal Nature Physics.
