This was achieved because the Innsbruck quantum physicists have an ion trap in which they can precisely set the distance between the ions and dielectric optics. Based on an earlier proposal by Rainer Blatt's group, the physicists computed the amount of noise caused by the dielectric material for this ion trap and compared it with data from the experiment. To calculate the noise, the so-called fluctuation-dissipation theorem from statistical physics was used, which mathematically describes the response of a system in thermal equilibrium to a small external perturbation.
Physicists have long suspected that dielectric materials may significantly disrupt ion-trap quantum computers. Now, researchers led by Tracy Northup have developed a new method to quantify this source of error for the first time. For the future operation of quantum computers with very many quantum bits, such noise sources need to be eliminated already during the design process if possible.
For more information see:
Publication: Heating of a trapped ion induced by dielectric materials. Markus Teller, Dario A. Fioretto, Philip C. Holz, Philipp Schindler, Viktor Messerer, Klemens Schüppert, Yueyang Zou, Rainer Blatt, John Chiaverini, Jeremy Sage, and Tracy E. Northup. Phys. Rev. Lett. 126, 230505 doi: 10.1103/PhysRevLett.126.230505