96th CEMS Colloquium

Title

Advances in quantum dots towards photonics

Abstract

    Despite the growing interest in quantum technology, especially in quantum computers based on entangled states, quantum devices utilizing conventional quantum transitions remain important from the perspective of making quantum technology socially viable in the next decade. In line with this direction, the physics of manipulating quantum interactions and the development of new quantum materials are being actively pursued.

   One of the fundamental structures for realizing these quantum technologies is the quantum dot. The quantum dot was proposed 40 years ago and has been developed in the field of photonics and electronics by understanding its physics and establishing technologies for realization including crystal-growth techniques. In particular, quantum dot lasers have already been implemented as the first practical quantum mechanical devices that exploit the fully discrete nature of electron energy; about one million chips are shipped to the market annually by a venture company. Quantum dot lasers are also expected to play a leading role in silicon-based photonic and electronic convergent systems due to their ability to operate at high temperatures. Eventually, all high-performance computers and automobiles will be equipped with quantum-dot lasers. Needless to say, quantum dots are also employed as nanostructures that enable control of electrons, photons, spins, and phonons for quantum bits and single-photon sources as well as  highly efficient solar cells, displays, and biomarkers.

   In this colloquium, after providing a historical overview and clarifying physics basis of quantum dots, the recent advances in quantum-dot lasers and single photon sources are discussed. Moreover, solid-state cavity quantum electrodynamics based on quantum dots and photonic nanostructures is also presented. These discussions will highlight the significance of quantum dot photonics as an engineering discipline.