Quantum ground state of rotation achieved for the first time in two dimensions

Researchers at the University of Vienna, TU Wien, and Ulm University achieved the first-ever quantum ground state cooling of a levitated silica nanorotor’s rotational motion in two dimensions. The breakthrough demonstrates precise control over a nanoparticle’s orientation, pushing quantum mechanics’ limits by minimizing rotational energy to its absolute quantum minimum. This experiment marks the first time rotational motion has been cooled to its ground state in two orientational degrees of freedom, surpassing previous single-axis achievements. The team used advanced cooling techniques to suppress thermal noise, revealing quantum behavior in macroscopic objects—bridging classical and quantum physics. This milestone could enable ultra-sensitive quantum sensors and new tests of quantum mechanics at larger scales, advancing nanotechnology and fundamental physics research.