Quantum sensing with hot atomic vapors

Ilja Gerhardt

K. Mouloudakis, Iannis K. Kominis

Spin-exchange collisions in alkali or alkali-noble gas vapors are at the basis of quantum sensing, nucleon structure studies, tests of fundamental symmetries, and medical imaging. We here show that spin-exchange collisions in hot alkali vapors naturally produce strong bipartite entanglement, which we explicitly quantify using the tools of quantum information science. This entanglement is shown to have a lifetime at least as long as the spin-exchange relaxation time, and to directly affect measurable spin noise observables. This is a formal theoretical demonstration that a hot and dense atomic vapor dominated by random spin-exchange collisions can support long-lived bipartite and possibly higher-order entanglement.

Prineha Narang

Gisung Sim, Heewoo Kim, Han Seb Moon

Abstract Squeezed states of light, generated through four-wave mixing (FWM), are increasingly recognized as valuable resources for various applications in quantum sensing, quantum imaging, and quantum information processing. In this study, we report achieving more than − 7.8 dB of intensity-difference squeezing (IDS) in two-mode squeezed states from hot 85Rb vapor and − 5.0 dB from hot 87Rb vapor, utilizing a fiber electro-optic modulator (EOM) within a single home-made diode laser system. By mitigating the effects of undesired multimode from the EOM on the squeezing, we experimentally demonstrated the IDS of 85Rb and 87Rb atoms within a single experimental setup, benefiting from the EOM's ability to provide higher frequency shifts. This advancement may expand the scope of applications for hot atomic-vapor-based quantum technologies, leveraging the capabilities of the EOM.

Dong-Sheng Ding, Zhi‐Yuan Zhou, Bao‐Sen Shi +2 more

The efficient wavelength conversion of images has many potential applications in optical communication, sensing, imaging, and quantum information fields. In this work, we report on a demonstration of an image transfer between light of wavelength 780 nm and light of wavelength 1530 nm by performing two sequential four-wave-mixing processes in two different hot atomic rubidium vapor cells. Furthermore, we confirm experimentally the persistence of coherence of the input light during this sequential process. Our results may be useful to the research fields mentioned above.