Prof. Yi-Hsin Chen (陳易馨)
Department of Physics, National Tsing Hua University
Date 2017.02.23(Thu)
Time 10:30am
Place S4-625
Abstract:
Photons play a key role in the growing field of quantum information science, due to their weak free-space interactions. The optical non-linearity via a medium is proportional to the light intensity. Therefore, to have the ability of manipulating a single photon is a big challenge. I will first present our previous studies on EIT (electromagnetically induced transparency)-based optical manipulation including the demonstrations of a high-efficiency optical memory, optical frequency converter, all-optical switch, and all-optical phase modulator. The above-mentioned studies were carried out by coherence light interacted with laser-cooled atoms (around 300 K). Due to the quantum nature
,the light-matter interface can be also applied to single-photon quantum state.
A deterministic single-photon source is the basic ingredient for quantum manipulation. In the second part of my talk, I will report the generation of single-photon source based on the combination of four-wave-mixing (FWM) and Rydberg blockade effect in a thermal vapor (round 150C) confined in a cell with micrometer scale, which was done in Stuttgart University in Germany. The atomic transition involving Rydberg state induces the strong dipole-dipole interaction, which can further enhance the interaction between individual photons, making single-photon-level quantum state
manipulation achievable.
Finally, I will carry out my research plan on the studies of nonlinear photon-photon interactions with surrounding atoms along with optical nanofibers (sub-micron in diameter). The fiber-based integrated devices have long interacting length without divergent, large optical depth, and potential nonlinear interactions at low-light level as well as single-photon level. These advantages enable the development of all-fibered quantum systems and that have potential
applications in quantum information science.