Hy-Q-researchers bring new standard for precision in quantum measurements

04. June 2019

For more than 50 years, quantum researchers have tried to push the so-called SQL limit for precision in sensitive quantum measurements. Now, a research team from the DNRF’s Center for Hybrid Quantum Networks (Hy-Q) at the Niels Bohr Institute has solved the problem with the help of a simple modification. Thus, the research team has developed a new standard for precision measurements of force and position on a quantum level. The result was recently published in the scientific journal Nature Physics.

The picture shows the three Hy-Q-researchers behind the study: Ph.D. students Junxin Chen and Massimiliano Rossi stand on either side of David Mason, who is the lead author of the article.
The picture shows the three Hy-Q-researchers behind the study: Ph.D. students Junxin Chen and Massimiliano Rossi stand on either side of David Mason, who is the lead author of the article.

In November of last year, the DNRF wrote an article about a new research method for quantum measurements developed by a research team from the Niels Bohr Institute and the Center of Excellence Hy-Q. Read the article about the method for quantum measurements here. Using the method, the same research team, including Yeghishe Tsaturyan, the two Ph.D. students Chen and Rossi, and post-doc David Mason, and Professor Albert Schliesser, has pushed the limits for precision measurements of force and position on a quantum level. Their experiment is the first ever to beat the so-called “standard quantum limit” (SQL), which occurs in the most ordinary optical techniques for ultraprecise position measurements.

“The SQL is something of a gold standard for the quality of a measurement. It is nothing that can’t fundamentally be overcome, but as far as force and position measurements are concerned, it turned out to be very hard. Even LIGO [the Laser Interferometer Gravitational Wave Observatory] isn’t there yet. But with our system we thought we should stand a chance,“ said Professor Schliesser, senior author behind the study.

Mason, a post-doc at Hy-Q and lead author of the study added:

“Once we knew we could get very close to the SQL, the modifications required to beat it were actually rather straightforward,” Mason explained. He continued: “We are using quantum effects that arise in the measurement setup itself, so the extra technological effort is actually limited. That is good news for potential practical applications.”

Read the scientific publication in Nature Physics here

Further information about the study can be found in a press release from the Niels Bohr Institute here