Coherent matter-wave optics is still a very young field, far less developed and more complex than conventional optics for light. This field represents an emerging area of science, quantum engineering, with a high potential for a future technology and multidisciplinary applications.

Thanks to an impressive evolution and remarkable inventions, the ultimate potential of matter-wave sensors is entirely open. For the closely related field of atomic clocks, the growth in performance was exponential during the last decades! This is the reason why matter-wave sensors are considered as one of the most promising fields to progress in metrology and fundamental tests. On the other hand, it is still an open question, if quantum engineering will become a technology with major applications (beyond clocks) in everyday life. Inertial quantum sensors provide a new tool for the precise detection of faint forces and tiny rotations. 

Our research is focused on the investigation of different aspects of gravitational physics using cold atom quantum sensors.

Atom interferometry with alkaline-earth & alkaline-earth like atoms 

We are currently developing and studying new interferometric schemes based on ultra-cold strontium and cadmium atoms. The aim of the project is high precision measurements of gravity acceleration for fundamental tests of General Relativity.

Atom interferometry gravity-gradiometer for the determination of the Newtonian gravitational constant G 

The goal of the experiment is the high precision measurement of the Newtonian gravitational constant G using atom interferometry. More than 300 measurements have been performed to measure G but there are only a few methods which can be considered conceptually different from the first one by Cavendish.

In our experiment, freely falling cold Rb atoms are used as the probe to measure the gravitational acceleration due to nearby source masses. The combination of Raman atom interferometry and laser cooling will allow us to achieve high sensitivity. Using atoms with well known properties, instead of macroscopic probe masses, will help to reduce systematic errors aiming at a relative precision of 10-5.

Non-classical sources for atom interferometers and optical clocks 

Atom interferometers and optical clocks are now reaching the precision limits imposed by quantum mechanics. This so-called Standard Quantum Limit arises in phase shift estimation operated with uncorrelated atoms. Our goal is to study and develop a new kind of sensor that exploits quantum entanglement in order to surpass the Standard Quantum Limit in atom interferometry. We are currently implementing an apparatus that combines atom interferometry with strontium atoms and an optical cavity used to generate entanglement between atoms. The goal is the demonstration of metrological gain in atom interferometer precision compared to the Standard Quantum Limit. Atom interferometry with entangled atoms is a new and interesting field both for fundamental physics and for various applications. The developed prototype will contribute in triggering a new class of quantum-enhanced sensors.

Interferometry with anti-matter 

The QUPLAS (QUantum interferometry and gravitation with Positrons and LASers) experiment is dedicated to the study of positron and positronium interferometry and gravitation as well as other quantum mechanical effects using fundamental fermions. QUPLAS is a Como, Milano, Brescia, Firenze, Modena-Reggio, Napoli collaboration. https://www.positron.fisi.polimi.it