“Embracing Illumination: Multiple Photons Outshine Singular Ones in Advancing Quantum Technologies”

Quantum entities, such as electrons and photons, exhibit distinctive behaviors distinguishing them from other objects, paving the way for advancements in quantum technology. The exploration of quantum entanglement, wherein multiple photons exist in various modes or frequencies, holds the key to unraveling this mystery.

In the pursuit of photonic quantum technologies, earlier investigations have confirmed the efficacy of Fock states. These states, encompassing multiple photons and modes, result from skillfully combining one-photon inputs through linear optics. Nonetheless, certain crucial and valuable quantum states demand a more sophisticated approach beyond the traditional photon-by-photon method.

A group of researchers from Kyoto University and Hiroshima University has both theoretically and experimentally verified the distinct advantages of non-Fock states—referred to as iNFS. These intricate quantum states go beyond a single photon source and linear optical elements. The findings have been published in the journal Science Advances.

Shigeki Takeuchi, corresponding author from the Graduate School of Engineering, highlights, “We have successfully validated the presence of iNFS using an optical quantum circuit involving multiple photons.” Geobae Park, a co-author, emphasizes the potential impact on applications such as optical quantum computers and optical quantum sensing, stating,

“Our study will pave the way for breakthroughs in applications such as optical quantum computers and optical quantum sensing.” The photon emerges as a promising carrier due to its ability to maintain its quantum state over extended distances at constant room temperature. The aggregation of numerous photons in various modes holds the promise of enabling long-distance applications like optical quantum cryptography, optical quantum sensing, and optical quantum computing. Ryo Okamoto, another co-author, elaborates on the research process, noting,

“We meticulously generated a complex form of iNFS by employing our Fourier transform photonic quantum circuit to exhibit two photons in three different pathways, representing the most challenging manifestation of conditional coherence.” Furthermore, the study contrasts iNFS with quantum entanglement, a widely applied phenomenon that arises and disappears with the passage through a single linear optical element. Quantum entanglement involves correlated states in a superposition between separate systems. Holger F Hofmann, a co-author from Hiroshima University, underscores a significant finding, stating, “Remarkably, this study reveals that iNFS properties remain unchanged when traversing a network of many linear optical elements, signifying a breakthrough in optical quantum technology.

” Takeuchi’s team proposes that iNFS demonstrates conditional coherence, a somewhat mysterious phenomenon where the detection of a single photon implies the existence of remaining photons in a superposition of multiple pathways. Looking ahead, Takeuchi announces the team’s next objective: “Our next phase is to realize larger-scale multiphoton, multimode states, and optical quantum circuit chips.”

This article is republished from PhysORG under a Creative Commons license. Read the original article.