"Strong light-matter interactions in semiconductor quantum dots coupled to photonic crystals"

TYPESpecial Seminar - Solid State Institute, Technion
Speaker:Professor Edo Wax
Affiliation:Dept. of Electrical and Computer Engineering, Univ. of Maryland, College Park, U.S.A.
Location:Solid State Auditorium(Entrance)
Remark:Host: Prof. David Gershoni

Two dimensional photonic crystals have been recognized as a highly promising scalable platform for compact integrated photonics. Another important aspect of photonic crystals is their ability to localize and trap light to spatial volumes on the order of a cubic wavelength, resulting in extremely high electromagnetic intensities. Recently, it has been shown that by embedding a single quantum dot (QD) in the high field region of photonic crystal cavities it becomes possible to achieve strong light-matter interactions at the single photon/single atom level. These unprecedented interaction strengths open up the possibility for creating nonlinear optical effects approaching the single photon level. In addition, they can be exploited to engineer unique quantum mechanically entangled states of light and matter that enable scalable quantum networks. In this talk, I will discuss our work on coupling indium arsenide (InAs) QDs to photonic crystal structures for creating nonlinear optical interactions at low photon numbers, and for storing and transferring quantum information from QD spin to photons. I will describe an experimental demonstration of giant optical Stark shifts with only 10 photons of energy using a strongly coupled cavity-QD system, and a more recent demonstration of all-optical switching with only 150 photons of control energy. I will then discuss our work on coupling QD spin to light in order to realize a quantum transistor that can exhibit the quantum mechanical property of entanglement. The quantum transistor could enable a novel class of opto-electronic devices that serve as a fundamental building block for quantum computers and quantum networks.


Edo Waks is a professor in the Department of Electrical and Computer Engineering at the University of Maryland, College Park. He is also a member of the Joint Quantum Institute (JQI), a collaborative effort between the University of Maryland and the National Institute of Standards and Technology (NIST) at Gaithersburg, dedicated to the study of quantum coherence. Waks received his B.S. and M.S. from Johns Hopkins University, and his Ph.D. from Stanford University. He is a recipient of an NSF CAREER award as well as a Presidential Early Career Award for Scientists and Engineers (PECASE) for the investigation of interactions between quantum dots and nanophotonic structures. His current work focuses on coherent control and manipulation semiconductor quantum dots, and their interactions with photonic crystal devices for creating strong atom-photon interactions.