islamabad   -  Study by the University of Bonn determines minimum time for complex quantum operations. Suppose you observe a waiter (the lockdown is already history) who on New Year’s Eve has to serve an entire tray of champagne glasses just a few minutes before midnight. He rushes from guest to guest at top speed. 

Thanks to his technique, perfected over many years of work, he nevertheless manages not to spill even a single drop of the precious liquid. A little trick helps him to do this: While the waiter accelerates his steps, he tilts the tray a bit so that the champagne does not spill out of the glasses. Halfway to the table, he tilts it in the opposite direction and slows down. Only when he has come to a complete stop does he hold it upright again. Atoms are in some ways similar to champagne. They can be described as waves of matter, which behave not like a billiard ball but more like a liquid. 

Anyone who wants to transport atoms from one place to another as quickly as possible must therefore be as skillful as the waiter on New Year’s Eve. “And even then, there is a speed limit that this transport cannot exceed,” explains Dr. Andrea Alberti, who led this study at the Institute of Applied Physics of the University of Bonn.