Eugene Polzik - Quantum mechanics in the negative mass reference frame

Virtual Lecture

Lecture available on YouTube


According to textbook quantum mechanics, a measurement of the position of an object imposes a random quantum back action kick to its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence, and in accordance with the Heisenberg uncertainty principle, this leads to the so-called standard quantum limit on the precision of sensing of position and force. Similar quantum limits are found if a spin oscillating in magnetic field is monitored. In this talk I will present the ideas and experimental results for measurement of motion of a mechanical or a spin oscillator with, in principle, unlimited precision. This is achieved by performing a measurement in a special reference frame with an effective negative mass. Applications to force sensing, magnetometry and gravitational wave detection will be discussed.

Nature Physics (2020) 10.1038/s41567-020-1031-5.

Phys. Rev. Lett. 121, 031101 (2018).

Nature, 547, 191 (2017).

PRL 104, 133601 (2010).


Eugene Polzik is professor of physics at the Niels Bohr Institute at the University of Copenhagen and the leader of QUANTOP – Quantum Optics Center. His research interests are within quantum physics of matter and light, quantum communication, quantum sensing, and quantum information technologies. Among his notable results are demonstration of the quantum teleportation between material objects, a quantum memory for light, an optical detection of radio waves using a nanomechanical oscillator, a quantum optical interface with a cold atomic crystal, and measurements of motion and fields not restricted by the Heisenberg uncertainty.

Eugene Polzik has published more than 170 papers in refereed journals including a number of papers in Science and Nature journals. For the complete list of publications see

Eugene Polzik is a member of the Royal Danish Academy of Sciences, Fellow of the American Physical Society and Fellow of the Optical Society of America. He is a recipient of several awards. including the Herbert Walther Award of Optical Society of America and German Physical Society, the Gordon Moore Distinguished Scholar award, the Scientific American Research Leadership award, the European Research Council Advanced Grant award (twice) and the Danish Association of Academics award.


MPL Research Centers and Schools