https://scholar.korea.ac.kr/handle/2021.sw.korea/335 2026-04-05T17:22:45Z 2026-04-05T17:22:45Z CHAE Eunmi https://scholar.korea.ac.kr/handle/2021.sw.korea/279859 2026-01-18T08:43:41Z 2025-09-01T00:00:00Z

Title: 처음 만나는 양자의 세계 : 양자 역학부터 양자 컴퓨터까지 Authors: CHAE Eunmi

2025-09-01T00:00:00Z Junegone Chay https://scholar.korea.ac.kr/handle/2021.sw.korea/279867 2026-01-18T09:28:28Z 2025-08-01T00:00:00Z

Title: 양자컴퓨팅 및 정보 - 스캐폴딩 접근방식 Authors: Junegone Chay

2025-08-01T00:00:00Z Lee, Dayoung Ahn, Jung Keun Nam, Seung-il https://scholar.korea.ac.kr/handle/2021.sw.korea/270680 2025-06-04T09:01:44Z 2025-07-01T00:00:00Z

Title: Double ϕ production in p¯p reactions near threshold Authors: Lee, Dayoung; Ahn, Jung Keun; Nam, Seung-il Abstract: We employ an effective Lagrangian approach to investigate double ϕ production in the p¯p reaction near the threshold and describe a notable violation of the Okubo-Zweig-Iizuka (OZI) rule in this reaction process through hadronic degrees of freedom, using the currently available theoretical and experimental information. The ground-state nucleon and its s-wave resonances, i.e., N⁎(1535,1650,1895), are taken into account in the t- and u-channel tree-level diagrams. The pentaquark-like nucleon resonance Ps(2071,3/2−) is also considered. In the s-channel diagrams, scalar and tensor mesons are incorporated, specifically f0(2020,2100,2200) and f2(1950,2010,2150), respectively, along with the pseudoscalar meson η(2225). Our calculations suggest that contributions from the N and N⁎ resonances significantly enhance the cross-section near the threshold. At the same time, those from the f0 and f2 mesons produce distinctive peak structures around W=2.2 GeV, qualitatively reproducing the JETSET experimental data. The openings of the Λ¯Λ and Σ¯Σ channels lead to the cusp structures, which can explain the nontrivial structures in the cross-section at W≈2MΛ and 2MΣ observed in the data. It turns out that contributions from the η and Ps resonances are almost negligible. Additionally, polarization observables such as the spin density matrix element (SDME) provide crucial insights into the individual hadronic processes involved in this reaction. © 2025 The Author(s)

2025-07-01T00:00:00Z Kim, Ilhwan Kim, Yosep Kim, Yong-Su Lee, Kwang Jo Lim, Hyang-Tag https://scholar.korea.ac.kr/handle/2021.sw.korea/271436 2025-06-05T09:02:42Z 2025-06-02T00:00:00Z

Title: Robust and bright polarization-entangled photon sources exploiting non-critical phase matching without periodic poling Authors: Kim, Ilhwan; Kim, Yosep; Kim, Yong-Su; Lee, Kwang Jo; Lim, Hyang-Tag Abstract: Entangled photon sources are essential for quantum information applications, including quantum computation, quantum communication, and quantum metrology. Periodically poled (PP) crystals are commonly used to generate bright photon sources through quasi-phase matching. However, fabricating uniform micron-scale periodic structures poses significant technical difficulties, typically limiting the crystal thickness to less than a millimeter. Here, we adopt non-critical phase matching to produce a robust and bright polarization-entangled photon source based on a bulk KTP crystal located in a Sagnac interferometer. This method is tolerant to variations in pump incidence angles and temperature, and theoretically offers about a 2.5-fold brightness enhancement compared to quasi-phase matching at a specific wavelength. Additionally, the absence of periodic poling allows for a larger crystal cross-section. Using a bulk KTP crystal without a PP structure, we experimentally produce the four Bell states with a brightness of 25.1 kHz/mW at a wavelength of 1079 nm, achieving purity, concurrence, and fidelity values close to 0.99. We believe our scheme will serve as a key building block for scalable and practical photonic quantum information applications. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

2025-06-02T00:00:00Z