报告题目：Contactless photon-photon interactions
主持人：黄国翔 教授
时间：2018-1-25 10:00
地点：理科大楼A814
报告人简介：
Academic Career：
BA Physics, 1st class, Oxford University 1986;
MEng Engineering Physics, McMaster University 1988;
PhD Physics, Strathclyde University 1991;
Royal Society European Research Fellowship, Konstanz University, 1992;
Lindemann Fellowship, Stanford University, 1994;
Lecturer Durham University, 1995;
Professor Durham University, 2003;
Director of the Joint Quantum Centre, Durham University 2012.
Current interests:
In 2006 we began working on highly excited Rydberg atoms. In particular, we are interested in exploiting the large (long wavelength) dipoles associated with Rydberg states to enhance optical nonlinearities at the single photon level, for applications in quantum optics and quantum information processing. We first demonstrated the cooperative enhancement of the non-linearity due to dipole-dipole interactions in 2010. More recently, we have also begun looking at dipole-dipole interactions using only shorter wavelength optical dipoles. More information is available on the research pages of our cold and hot atom experiments.
Publication Record:
Publications >150 refereed articles;
Citations 4367, with h-index of 27.
报告内容简介：
The experimental demonstration of electromagnetically induced transparency (EIT) involving highly-excited Rydberg atoms [1] opened the door to a new field of quantum non-linear optics mediated by dipolar interactions between highly-excited Rydberg atoms [2]. A unique feature of Rydberg quantum optics is the ability of photons to interact without ever being in the same medium. Recently, we demonstrated repulsion between two photons separated by 15 times their wavelength [3]. Each photon experiences a position dependent refractive index induced by the photon stored in the adjacent medium, as illustrated in the Fig. 1.
Fig. 1: Propagation of photons (red) through two independent media (grey) separated by a distance, d. The photons are stored in collective superpositions involving highly-excited Rydberg states which interact via long-range van der Waals interactions. The interactions imprint a phase gradient on the superposition state (shown below) leading to a deflection of the outgoing photons. The inset shows the case of a single channel.
Such long-range interactions between photons provide an interesting platform for scalable multichannel photonic devices, or quantum simulation of strongly-correlated many-body dynamics using light.
[1] A. Mohapatra et al, Phys Rev Lett. 98, 113003 (2007).
[2] O. Firstenberg, C. S. Adams, and S. Hofferberth, J Phys B 49, 152003 (2016).
[3] H. Busche et al., Nature Phys. 13, 655 (2017).