报告人：白正阳, 副研究员 (华东师范大学)

时 间：2024年1月9号（周四）上午11:00

地 点：中关村校区，计算中心楼110会议室

摘要：

The strong interactions between Rydberg atoms provide a good platform for studying nonlinear quantum optics in many-body systems [1]. We focus on the nonlinear features of light in Rydberg systems. The first part will introduce the optical nonlinearities of light pulses propagating in high number density, Rydberg atomic vapors. We show that using fast Rabi flopping and strong Rydberg atom interactions, both in the order of gigahertz, can overcome the Doppler effect as well as collisional decay, leading to a sizable dispersive optical nonlinearity on nanosecond timescales. In this regime, self-induced transparency (SIT) emerges when areas of the nanosecond pulse are determined primarily by the Rydberg atom interaction, rather than the area theorem of interaction-free SIT [2]. The second part will introduce single-photon terahertz detection with thermal Rydberg atoms. The low-energy THz photons are coherently upconverted to the high-energy optical photons via six-wave-mixing process. The optimum quantum efficiency of the whole wave-mixing process is about 4.3% with 40.6 dB dynamic range and the maximum conversion bandwidth is 172 MHz. The noise equivalent power of such a detector is reached to be 9.510-19 W/Hz1/2, which is more than four orders of magnitude lower than the state-of-the-art room temperature THz detectors [3].

Reference

[1] M. Saffman, T. G. Walker, and K. Mølmer, Rev. Mod. Phys.82, 2313 (2010).

[2] Z. Bai, C. S. Adams, G. Huang, W.. Li, Phys. Rev. Lett. 125, 263605 (2020).

[3] D. Li, Z. Bai, X. Zuo, Y. Wu, J. Sheng, H. Wu, Appl. Phys. Rev. 11, 041420 (2024).

简历：

白正阳，华东师范大学副研究员。博士毕业于华东师范大学精密光谱科学与技术国家重点实验室，2018-2020年在英国诺丁汉大学开展博士后研究，2020-至今任职华东师范大学。目前的研究兴趣主要围绕光与原子相互作用产生的若干非线性与非平衡物理问题，具体研究方向包括：光学孤子的形成与传输、多体系统中非平衡动力学相变、量子信息与量子测量等。目前，已在包括Physical Review Letters, Science Advances, Optica, Applied Physics Reviews等学术刊物发表文章30余篇，部分理论预言被国内外实验组证实。先后获得上海市自然科学二等奖（第二完成人）、上海市浦江人才等项目资助。

联系方式：bozhang_quantum@bit.edu.cn

邀请人： 张博

网 址：http:/

承办单位：物理学院、量子技术研究中心