ESPCSS · Efficient Spin-Photon Coupling in the Solid-State

Efficient Spin-Photon Coupling in the Solid-State

"The central problem addressed in this research is how to efficiently couple single electrons and single photons in a controllable and repeatable manner. Free-space approaches to this problem typically suffer from two obstacles; the difficulty in isolating single electrons hinders efficient photon absorption, while the isotropic nature of photon emission leads to photon loss and low efficiencies. In order to overcome these problems, this research aims to take a solid-state approach, in which electrons are confined and localised in semiconductor nanostructures known as ""Quantum Dots"", which can in principle allow for efficient and coherent electron-photon coupling. Using these solid-state nanostructures, however, introduces additional problems, such as coupling to lattice vibrations and nuclear spins in the solid. The purpose of this research was to understand and design ways in which these effects could be minimised, necessitating the development of new theoretical techniques to model such systems. The efficient coupling of single electrons and single spins would represent significant milestone in our ability to control the microscopic realm, and by extension would be of huge importance to a number of technologies which promise to impact society. In particular, nearly all quantum technologies rely on coupling two or more quantum systems and in an efficient and controlled manner. This is especially true in photonic quantum computing architectures, as well as quantum communication protocols using quantum repeaters. At the heart of these schemes lie photon-photon and photon-electron interactions, and a major challenge in these cases is achieving these interactions with sufficient efficiency that the advantage of exploiting quantum mechanical interactions is not lost. A successful quantum communication network would allow for completely secure communication channels, while an operational quantum computer has the potential to transform how we approach computation problems, and could lead to methods of, for example, drug discovery, which are completely beyond the reach of conventional computers. With this in mind, the objectives of this research are to: 1) Develop and new theoretical framework of solid-state electron-photon coupling, which would allow for an accurate description of light-matter coupling quantum dots, and 2) Use this framework to develop ways in which the solid-state environment in quantum dots can be controlled and modified to increase the efficiency and controllability of electron-photon coupling. This research concluded with the establishment of such a theoretical framework, with which it has been possible to place quantitative bounds on the impact of lattice vibrations on electron-photon coupling in quantum dots in a number of settings, and the design of protocols which act to minimise the impact of coupling to nuclear spins."

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз