Physicists create the world's largest stationary quantum state

Jun, 2021 - By WMR

For decades, scientists have been able to cool atoms and groups of atoms to a fraction of absolute zero, resulting in the motional ground state which is a wonderful place to start if an individual want to make exotic states of matter like super solids or fluids with negative mass.

In the real world scales and quantum, the term "stationary" has radically different meanings; a thing that appears to be absolutely motionless to the humans, that is actually made up of atoms that are energetic and lively around. Scientists have now managed to bring the atoms to a near-complete halt in the world's largest macro-scale object. The mobility of an object's atoms is directly related to its temperature — in other words, the hotter something is, the more its atoms jitter around. By extension, there is a temperature at which the object's atoms come to a complete stop, which is known as absolute zero (-273.15 °C, -459.67 °F).

Superior objects, therefore, are more problematic to operate since they include more atoms, each of that communicate with their environs. Yet, a huge universal team of scientists has now set a new record for the largest object encouraged into a motional ground state. Normally, these studies are carried out on clouds containing millions of atoms, but the new test was carried out on a 10-kg (22-lb) mass containing about an octillion atoms. Surprisingly, that "item" isn't simply one thing, but the combined motion of four separate objects, each weighing 40 kg (88 lb).

In theory, cooling atoms is straightforward: simply oppose their motion with an equal and opposite force. But that necessitates incredibly exact measurements of their motion, and to make matters even more complicated, the process of measuring them can create a new force on them. Surprisingly, the current study took advantage of this to the team's benefit. As photons of light bounce off the mirrors in LIGO's lasers, they cause tiny bumps, which may be recorded in subsequent photons. The scientists have lots of data regarding the motions of the atoms in the mirrors since the beams are constant, allowing them to build the appropriate counteracting forces.