Eugene Polzik
Niels Bohr Institute, University of Copenhagen
Copenhagen — Denmark
Quantum mechanics in the negative mass reference frame
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, forces and fields. In this talk I will present the ideas and experimental results for measurement of motion of a mechanical oscillator with, in principle, unlimited precision. This is achieved by measuring the motion in a special reference frame with an effective negative mass. Entanglement of the system of interest and the reference frame leads to cancellation of the quantum back action of the measurement which is the origin of the standard quantum limit. Applications to force sensing, and gravitational wave detection will be discussed.
