Prof. Marco Fattori - Mach-Zehnder atom interferometry with non-interacting trapped Bose-Einstein condensates

Mach-Zehnder atom interferometry with non-interacting trapped Bose-Einstein condensates

M. Fattori^1,2

¹ Lens and Dipartimento di Fisica e Astronomia, Università di Firenze, Italy

² CNR Istituto Nazionale di Ottica, Sesto Fiorentino & Lecce, Italy

The coherent control of matter waves lies at the heart of quantum sensing. In atom interferometry, beam splitting and recombination are used to map phase shifts onto measurable population imbalances. While Bose–Einstein condensates (BECs) provide an ideal source of coherent matter waves, their use in double-well interferometers has long been limited by strong interparticle interactions that dominate over the tunneling energy.

In this seminar, I will present our recent work overcoming this limitation by employing BECs with tunable interactions in an array of double-well potentials [1]. By exploiting quantum tunneling, we realize coherent beam splitting and operate multiple Mach–Zehnder interferometers in parallel. A differential analysis allows us to cancel common-mode potential fluctuations, enabling the realization of a trapped-atom gradiometer. Moreover, the implementation of spin-echo techniques significantly suppresses decoherence, leading to coherence times approaching one second [2].

I will discuss the perspectives of this platform for precision force measurements with sub-micron spatial resolution and for quantum-enhanced sensing beyond the shot-noise limit. Finally, I will outline future directions, including the use of long-range dipolar interactions to emulate gravity-induced decoherence between neighboring interferometers [3, 4] and the generation of highly entangled states for tests of quantum wave-function collapse models [5].

[1] T. Petrucciani, A, Santoni, et al. “Long-wavelength optical lattices from optical beatnotes: Theory and applications”, Phys. Rev. A 112, 043323 (2025).

[2] T. Petrucciani, A, Santoni, et al. “Mach-Zehnder atom interferometry with non-interacting trapped Bose-Einstein condensates”, Nat. Commun. 17, 3948 (2026)

[3] Y. Trifa, D. Cafasso, M. Fattori and L. Pezzè, “Analogue many-body gravitating quantum systems with a network of dipolar Bose-Einstein condensates”, arXiv:2602.23319. 

[4] C. Marletto and V. Vedral, “Gravitationally induced entanglement between two massive particles is sufficient evidence of quantum effects in gravity”, Phys. Rev. Lett. 119, 240402 (2017)

[5] A. Bassi, K. Lochan, S. Satin, T. P. Singh, H. Ulbricht, “Models of wave-function collapse, underlying theories, and experimental tests”, Rev. of Mod. Phys. 85, 471 (2013)