We present and analyze a new approach for the generation of atomic spin-squeezed states. Our method involves the collective coupling of an atomic ensemble to a decaying mode of an open optical cavity. We demonstrate the existence of a collective atomic dark state, decoupled from the radiation field. By explicitly constructing this state we find that it can feature spin squeezing bounded only by the Heisenberg limit. We show that such dark states can be deterministically prepared via dissipative means, thus turning dissipation into a resource for entanglement. The scaling of the phase sensitivity taking realistic imperfections into account is discussed.We present and analyze a new approach for the generation of atomic spin-squeezed states. Our method involves the collective coupling of an atomic ensemble to a decaying mode of an open optical cavity. We demonstrate the existence of a collective atomic dark state, decoupled from the radiation field. By explicitly constructing this state we find that it can feature spin squeezing bounded only by the Heisenberg limit. We show that such dark states can be deterministically prepared via dissipative means, thus turning dissipation into a resource for entanglement. The scaling of the phase sensitivity taking realistic imperfections into account is discussed.

arXiv:1209.1991Physical Review LettersMar 19, 2013178 citations

ASPECTS OF SQUEEZING IN ATOMIC STATES

Ram Narayan Deb

Jan 1, 20080 citations

Driven-dissipative four-mode squeezing of multilevel atoms in an optical cavity

Bhuvanesh Sundar, Diego Barberena, Ana María Rey +1 more

We utilize multilevel atoms trapped in a driven resonant optical cavity to produce scalable multimode squeezed states for quantum sensing and metrology. While superradiance or collective dissipative emission by itself has been typically a detrimental effect for entanglement generation in optical cavities, in the presence of additional drives it can also be used as an entanglement resource. In a recent work [B. Sundar, D. Barberena, A. M. Rey, and A. Pi\~neiro Orioli, companion paper, Phys. Rev. Lett. 132, 033601 (2024)], we described a protocol for the dissipative generation of two-mode squeezing in the dark state of a six-level system with only one relevant polarization. There we showed that up to two quadratures can be squeezed. Here, we develop a generalized analytic treatment to calculate the squeezing in any multilevel system where atoms can collectively decay by emitting light into two polarization modes in a cavity. We show that in this more general system up to four spin squeezed quadratures can be obtained. We study how finite-size effects constrain the reachable squeezing, and analytically compute the scaling with $N$ . Our findings are readily testable in current optical cavity experiments with alkaline-earth-like atoms.We utilize multilevel atoms trapped in a driven resonant optical cavity to produce scalable multimode squeezed states for quantum sensing and metrology. While superradiance or collective dissipative emission by itself has been typically a detrimental effect for entanglement generation in optical cavities, in the presence of additional drives it can also be used as an entanglement resource. In a recent work [B. Sundar, D. Barberena, A. M. Rey, and A. Pi\~neiro Orioli, companion paper, Phys. Rev. Lett. 132, 033601 (2024)], we described a protocol for the dissipative generation of two-mode squeezing in the dark state of a six-level system with only one relevant polarization. There we showed that up to two quadratures can be squeezed. Here, we develop a generalized analytic treatment to calculate the squeezing in any multilevel system where atoms can collectively decay by emitting light into two polarization modes in a cavity. We show that in this more general system up to four spin squeezed quadratures can be obtained. We study how finite-size effects constrain the reachable squeezing, and analytically compute the scaling with $N$. Our findings are readily testable in current optical cavity experiments with alkaline-earth-like atoms.

arXiv:2309.10717Physical Review AJan 17, 20244 citations

Spin squeezed states in a collective spin system coupling to a highly dissipative ancillary system

Emi Yukawa, Shane Dooley, Matsuzaki Yuichiro +3 more

The Japan Society of Applied PhysicsFeb 8, 20160 citations

Retrieval of cavity-generated atomic spin squeezing after free-space release

Yunfan Wu, Rajiv Krishnakumar, Julián Martínez-Rincón +3 more

We demonstrate that releasing atoms into free space from an optical lattice does not deteriorate cavity-generated spin squeezing for metrological purposes. In this work, an ensemble of $500\phantom{\rule{0.16em}{0ex}}000$ spin-squeezed atoms in a high-finesse optical cavity with near-uniform atom-cavity coupling is prepared, released into free space, recaptured in the cavity, and probed. Up to $\ensuremath{\sim}10$ dB of metrologically relevant squeezing is retrieved for $700\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}$ free-fall times, and decaying levels of squeezing are realized for up to 3 ms free-fall times. The degradation of squeezing results from loss of atom-cavity coupling homogeneity between the initial squeezed state generation and final collective state readout. A theoretical model is developed to quantify this degradation and this model is experimentally validated.We demonstrate that releasing atoms into free space from an optical lattice does not deteriorate cavity-generated spin squeezing for metrological purposes. In this work, an ensemble of $500\phantom{\rule{0.16em}{0ex}}000$ spin-squeezed atoms in a high-finesse optical cavity with near-uniform atom-cavity coupling is prepared, released into free space, recaptured in the cavity, and probed. Up to $\ensuremath{\sim}10$ dB of metrologically relevant squeezing is retrieved for $700\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}$ free-fall times, and decaying levels of squeezing are realized for up to 3 ms free-fall times. The degradation of squeezing results from loss of atom-cavity coupling homogeneity between the initial squeezed state generation and final collective state readout. A theoretical model is developed to quantify this degradation and this model is experimentally validated.

arXiv:1912.08334Physical Review AJul 30, 202011 citations

Measurement-induced spin squeezing in a cavity

Hiroki Saito

Jan 1, 20030 citations

N

. Our findings are readily testable in current optical cavity experiments with alkaline-earth-like atoms.

We demonstrate that releasing atoms into free space from an optical lattice does not deteriorate cavity-generated spin squeezing for metrological purposes. In this work, an ensemble of

500\phantom{\rule{0.16em}{0ex}}000

spin-squeezed atoms in a high-finesse optical cavity with near-uniform atom-cavity coupling is prepared, released into free space, recaptured in the cavity, and probed. Up to $\ensuremath{\sim}10$ dB of metrologically relevant squeezing is retrieved for $700\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}$ free-fall times, and decaying levels of squeezing are realized for up to 3 ms free-fall times. The degradation of squeezing results from loss of atom-cavity coupling homogeneity between the initial squeezed state generation and final collective state readout. A theoretical model is developed to quantify this degradation and this model is experimentally validated.