March 28, 2024

Unprecedented Breakthrough in Manipulating “Quantum Light”

Particularly, the scientists could determine the direct dead time between one photon and a pair of bound photons spreading off a single quantum dot, a type of artificially developed atom.
” This opens the door to the manipulation of what we can call quantum light,” Dr. Sahand Mahmoodian from the University of Sydney School of Physics and joint lead author of the research said.
Dr. Mahmoodian said: “This basic science opens the path for advances in quantum-enhanced measurement techniques and photonic quantum computing.”
Joint lead author Dr. Sahand Mahmoodian from the School of Physics at the University of Sydney Credit: The University of Sydney.
By observing how light interacted with matter more than a century ago, scientists discovered light was not a beam of particles, nor a wave pattern of energy– but exhibited both attributes, referred to as wave-particle duality.
The method light interacts with matter continues to enthrall scientists and the human imagination, both for its theoretical appeal and its powerful practical application.
Whether it be how light passes through the vast areas of the interstellar medium or the development of the laser, research study into light is a crucial science with crucial practical usages. Without these theoretical foundations, almost all contemporary innovation would be difficult. No smart phones, no international communication network, no computer systems, no GPS, no contemporary medical imaging.
Joint lead author Dr. Natasha Tomm from the Nano-Photonics Group at the University of Basel Credit: The University of Basel.
One advantage of utilizing light in communication– through optic fibers– is that packages of light energy, photons, do not quickly interact with each other. This creates near distortion-free transfer of info at light speed.
Nevertheless, we in some cases want light to engage. And here, things get difficult.
Light is used to measure little modifications in distance using instruments called interferometers. These measuring tools are now commonplace, whether it remain in sophisticated medical imaging, for essential but perhaps more prosaic tasks like carrying out quality assurance on milk, or in the kind of sophisticated instruments such as LIGO, which initially measured gravitational waves in 2015.
The laws of quantum mechanics set limits as to the level of sensitivity of such devices.
This limit is set between how delicate a measurement can be and the typical variety of photons in the measuring device. For classical laser light, this is different to quantum light.
Joint lead author, Dr. Natasha Tomm from the University of Basel, said: “The device we developed caused such strong interactions between photons that we had the ability to observe the distinction between one photon connecting with it compared to 2.
” We observed that one photon was delayed by a longer time compared to 2 photons. With this actually strong photon-photon interaction, the two photons become knotted in the form of what is called a two-photon bound state.”
Quantum light like this has an advantage because it can, in principle, make more sensitive measurements with better resolution utilizing less photons. When big light strengths can damage samples and where the features to be observed are particularly small, this can be crucial for applications in biological microscopy.
” By showing that we can determine and manipulate photon-bound states, we have actually taken an important first step towards utilizing quantum light for useful use,” Dr. Mahmoodian said.
” The next actions in my research study are to see how this technique can be utilized to produce states of light that work for fault-tolerant quantum computing, which is being pursued by multimillion-dollar companies, such as PsiQuantum and Xanadu.”
Dr. Tomm said: “This experiment is beautiful, not only due to the fact that it verifies a basic impact– stimulated emission– at its ultimate limitation, but it also represents a huge technological step towards advanced applications.
” We can apply the same concepts to establish more-efficient gadgets that give us photon bound states. This is very promising for applications in a vast array of areas: from biology to sophisticated manufacturing and quantum details processing.”
Reference: “Photon bound state dynamics from a single synthetic atom” by Natasha Tomm, Sahand Mahmoodian, Nadia O. Antoniadis, Rüdiger Schott, Sascha R. Valentin, Andreas D. Wieck, Arne Ludwig, Alisa Javadi and Richard J. Warburton, 20 March 2023, Nature Physics.DOI: 10.1038/ s41567-023-01997-6.
The research was a cooperation in between the University of Basel, Leibniz University Hannover, the University of Sydney, and Ruhr University Bochum.
The lead authors are Dr. Natasha Tomm from the University of Basel and Dr. Sahand Mahmoodian at the University of Sydney, where he is an Australian Research Council Future Fellow and Senior Lecturer.
The artificial atoms (quantum dots) were fabricated at Bochum and used in experiments performed in the Nano-Photonics Group at the University of Basel. Theoretical deal with the discovery was brought out by Dr. Mahmoodian at the University of Sydney and Leibniz University Hannover.
Financing: Swiss National Science Foundation, Australian Research Council, European Union Horizon 2020 Research, German Research Foundation, German Ministry of Education and Research.

Artists impression of how photons bound together after interaction with synthetic atom. Credit: The University of Basel
Photonic bound states could advance medical imaging and quantum computing.
For the first time, scientists at the University of Sydney and the University of Basel in Switzerland have demonstrated the ability to control and determine little numbers of connecting photons– packets of light energy– with high correlation.
This unmatched accomplishment represents an important landmark in the advancement of quantum innovations. Details of the research were released on March 20 in the journal Nature Physics.
Stimulated light emission, postulated by Einstein in 1916, is commonly observed for great deals of photons and laid the basis for the creation of the laser. With this research, promoted emission has actually now been observed for single photons.