research bits

Ness et al Science advances 12/2021

The research of Gal Ness and Yoav Sagi, in collaboration with the group of Dieter Meschede and Andrea Alberti at the University of Bonn

investigating the quantum speed limits, was published in the journal Science Advances.

The researchers have devised a neat experiment that determines the governing factors of the speed limit for quantum computations.
Quantum mechanics sets fundamental limits on how fast quantum states can evolve in time. Two well-known quantum speed limits are the Mandelstam–Tamm and the Margolus–Levitin bounds, which relate the maximum speed of state transfer to the system’s energy uncertainty and mean energy, respectively. The researchers test both limits in a multi-level system by following the motion of a single atom in an optical trap, leveraging fast matter-wave interferometry, a technique that enables high-precision detection of matter-wave differences. Their data reveal two different dynamical regimes: one where the Mandelstam–Tamm limit constrains the evolution at all times, and a second where a crossover to the Margolus–Levitin limit is manifested at longer times.
These results, providing the first experimental evidence of both limits in a multi-level quantum system in a single experiment, are essential for understanding the ultimate performance of quantum computing devices and related advanced quantum technologies.


Link to paper in Suence Advances.

Read the full article on the Technion website here


Photo Copyright: Rami Shlush, Technion Spokesperson's Office.

Image: Quantum marbles in action — an artistic illustration of a matter wave rolling down a steep potential hill. Credit: Enrique Sahagún – Scixel