Promotionsvortrag Physik: Narrowband quantum light sources and their use for quantum communication

Ankündigung des Promotionsvortrags von: Herrn Sheng-Hsuan Huang

Single-photon sources play a crucial role in quantum information processing. Among the various methods for generating single photons, spontaneous parametric down-conversion (SPDC) is one of the most widely used and has been implemented across different platforms. Among these, crystalline whispering-gallery-mode resonators (WGMRs) represent an intriguing platform for re-alizing SPDC-based sources. They have been shown to be capable of efficiently interacting with alkali atoms due to their narrow and tunable emission bandwidths. Moreover, they operate with relatively low pump power, which is advantageous for large-scale integration and power-con-strained applications.

Here, I will present three experiments conducted during my doctoral thesis to further demonstrate the versatility of WGMR-based SPDC sources. First, we generate polarization-entangled photon pairs using an interferometric scheme, achieving a Clauser-Horne-Shimony-Holt inequality pa-rameter of 𝑆𝑆=2.54±0.06, violating the classical bound by over eight standard deviations. Second, we observe Hong-Ou-Mandel interference with visibilities of 74% and 76% for photons from one and two independent WGMRs, respectively, using an in-coupled pump power as low as 50nW. Finally, we demonstrate photon-ion interaction between a WGMR-generated photon and a 174Yb+ ion with a success probability of 8%. Together, these results highlight the potential of WGMR-based SPDC sources for scalable quantum networks and hybrid quantum systems.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.