Measuring quantum systems usually forces them to a classical state, but scientists at the University of Seville and other European centers have successfully taken snapshots of one millionth of a second to “film” without destroying quantum information. The process. According to the magazine, this advancement can help correct errors in quantum computers and is one of the top ten in 2020. Physical world.
Annual magazine Physical world, Is the magazine of one of the largest physics society in the world, Institute of Physics (IOP), Highlighting the huge annual progress in this field. 2020 year New silicon-based luminous body This is a winning study, but of the 10 finalists for this prestigious award, one exists in Spain.
From Universities in Seville, Basque Country, Stockholm (Sweden) and Siegen (Germany) For the first time, I managed to “record” what happened during the measurement of the quantum system.Details have been published in the magazine Medical letter.
In order to carry out this work, Strontium ion (Charged atoms) are trapped in the electric field.
Ion measurement only needs Millionths of a secondBut the researchers managed to “live” the process by reconstructing the quantum state of the system at different times, thus confirming one of the most subtle predictions in quantum physics.
The co-author explained: “This experiment is very interesting for two reasons.” Adam CabelloFrom the Second Department of Applied Physics of the University of Seville, “On the one hand, it shows The change of quantum state during measurement is not instantaneous – As many people believe – but it happens gradually.”
Real quantum state, not theoretical
“In addition,” he added, “experiments have shown that quantum measurements can be retained The quantum state with the most information is the real process Occurs in nature, not a simple theoretical idealization”.
The results of the experiment are summarized in GIF animation The figure shows what happens to the quantum state of the ion in one millionth of a second, and is visualized by a three-dimensional three-dimensional panel. The height of the tower indicates the degree of overlap of possible quantum states.
The film shows how some of the covering layers gradually disappear during the measurement process, while in an ideal quantum measurement, other covering layers are retained.
He said: “Although measurements usually force quantum systems into a certain classical state, this work shows that certain measurements do not destroy all quantum information.” Physical world“And by using the’framework’ in the strontium ion experiment, the research team found that the measurement is not instantaneous, but gradually transforms the superimposed state into a classical state.
The researchers concluded: “Because the’weak’ measurement principle used by the team can detect errors in a quantum state without destroying the quantum state, this progress can be used to improve error correction in quantum computers.” magazine.
Fabian Pokorny, Chi Chi, Gerard Higgins, Adán Cabello, Matthias Kleinmann, Markus Hennrich. “Tracking the dynamics of ideal quantum measurements”. Physical Wright Pastor