Look at the quantum experiment
© Thomas Schweiger, Vienna University of Technology
Quantum information plays an important role in many technical applications of quantum physics. Now an international research team under the direction of Technical University of Vienna came up with something that until now was nothing more than a “strange guess”: Shared information of a quantum system does not scale with the volume, but with the area.
This is an exciting finding in that things behave very differently in the “real world”. The information contained in a book depends, for example, on the volume of the book and not on the area of its cover. This is different in the quantum world.
Quantum gas is not independent of each other
“Let’s imagine a gas container in which small particles fly around and behave like little balls,” says Mohammadamin Tajik from the Vienna Center for Quantum Science and Technology (VCQ) – Atomic Institute of the Vienna University of Technology. In such a case, the particles would not share any information with each other. In the quantum world, however, very well. Here they share information and can no longer be viewed independently of one another. “In such a quantum gas, the shared information is greater than zero, and it does not depend on the size of the subsystems – only on the outer surface of the subsystem,” explains Mohammadamin Tajik.
The assumption that it behaves differently than in the “real world” has now been tested in a complex experiment led by Jorg Schmiedmayer confirmed by the Vienna University of Technology. To do this, a cloud of ultracold atoms was examined. The particles were cooled down to just above absolute zero temperature and captured by an atom chip, because the quantum properties of the particles become increasingly important in extreme cold. In this way, information can spread more and more throughout the entire system.
Complicated experiment
According to Schmiedmayer, the experiment is “very challenging” because it requires complete information about the quantum system. “We get the information we need by disturbing the atoms a bit and then observing the dynamics that result. It is similar to throwing a stone into a pond in order to obtain information about the condition of the liquid and the pond from the resulting waves,” says Schmiedmayer.
In any case, the results of the experiment are extremely relevant for the study of quantum physics, because it affects everything from gravity to solid-state physics. The Max Planck Institute for Quantum Optics in Garching, the Free University of Berlin, ETH Zurich and New York University were also involved in the research. The study was „Nature Physics“ published.
