Photon-mediated interactions for quantum sensing and simulation.*

Harnessing photons to mediate interactions between laser-cooled atoms inside of high finesse optical cavities  opens new frontiers in quantum simulation and quantum sensing.  Our lab has used both photon-mediated interactions and the quantum measurement process to realize highly-entangled states with as much as 18 dB of directly observed phase resolution beyond the Standard Quantum Limit [1].  We recently applied these approaches to achieve the first entanglement-enhanced matterwave interferometer for inertial sensing [2] and to realize a squeezing-enhanced differential strontium atomic clock comparison [3].  We have expanded the toolbox of cavity-mediated interactions further to create 3 and 4-body interactions [4] and arbitrary all-to-all XYZ Hamiltonians, including a first realization of two-axis counter twisting [5]. We have applied this greatly expanded toolkit to directly enhance the coherence times of both matterwave interferometers [6,7] and optical atomic clocks [8] via a new collective recoil mechanism in which atoms collectively absorb the momentum carried by the photons.  In the area of quantum simulation, we have used these programmable interactions to explore several dynamical phase transitions [9,10] including an emulation of long-predicted dynamical phases of a BCS superconductor [11-13].  If time permits, I will briefly touch on harnessing dissipation to observe a superradiant phase transition [14] and continuous lasing between momentum states [15,16].

 

[1] Cox et al, Phys. Rev. Lett. 116(9) 093602  (2016).

[2] Greve, Luo et al, Nature, 610(7932) 472-477 (2022).

[3] Robinson et al, Nature Physics 20 208 (2024).

[4] Luo et al, arXiv:2410.12132, to appear in Science (2025).

[5] Luo et al, Nature Physics 1–8 Apr. (2025).

[6] Shankar et al, Quant. Sci. & Tech. 4(4) 045010 (2019).

[7] Luo et al,  Science 384 551 (2024).

[8] Niu et al, Phy. Rev. Lett. 134 (11) 113403 (2025).

[9] Norcia et al, Science 361 6399, 259 (2018).

[10] Muniz et al, Nature 580 602 (2020).

[11] Lewis-Swan et al, Phys. Rev. Lett. 126 (17) 173601 (2021).

[12] Young et al, Nature 625, 679-684 (2024).

[13] Young et al, Phys. Rev. Lett. 134 (18) 183404 (2025).

[14] Song et al, Science Advances 11(17) eadu5799 (2025).

[15] Cline et al, Phys. Rev. Lett. 134 (1)  013403 (2025).

[16] Schäfer et al, Nature Physics 1-7 Apr. (2025).