Researchers at the University of Waterloo's Institute for Quantum Computing (IQC) recorded an interaction between light and matter 10 times larger than previously seen. The strength of the interaction between photons and a qubit was so large that it opens the door to a realm of physics and applications unattainable until now.
The results appear in the paper, "Ultrastrong coupling of a single artificial atom to an electromagnetic continuum in the nonperturbative regime," published in Nature Physics.
This illustration shows a qubit attached to a waveguide where light in the form of microwaves enters and exits.
Credit: University of Waterloo
"We are enabling the investigation of light-matter interactions in a new domain in quantum optics," said Pol Forn-Diaz, a postdoctoral fellow at IQC and lead author of the paper. "The possibilities are exciting because our circuit could potentially act as a quantum simulator to study other interesting quantum systems in nature."
The ultrastrong coupling between photons and qubits may lead to the exploration of new physics related to biological processes, exotic materials such as high-temperature superconductors, and even relativistic physics.
To conduct their experiment, the researchers fabricated aluminum circuits in the University of Waterloo's Quantum NanoFab, and then cooled them in dilution refrigerators to a temperature as low as one per cent of a degree above absolute zero. The circuits become superconducting at these cold temperatures, meaning that they can carry a current without resistance or losing energy. These aluminum circuits, known as superconducting qubits, obey the laws of quantum mechanics and can behave as artificial atoms.
To control the quantum state of a superconducting circuit, the researchers sent photons using microwave pulses into the superconducting circuit and applied a small magnetic field through a coil inside the dilution refrigerator. By measuring the photon transmission, the researchers could define the resonance of the qubit, indicated by the reflection of the photons off the qubit. Usually, the qubit resonance is centered around a very narrow range of frequencies.
"We measured a range of frequencies broader than the qubit frequency itself," said Forn-Diaz. "This means there is a very strong interaction between the qubit and the photons. It is so strong that the qubit is seeing most of the photons that propagate in the circuit, which is a distinctive signature of ultrastrong coupling in an open system."
This work was carried out in a collaboration between the Waterloo-based experimental groups of Adrian Lupascu and Christopher Wilson. Both are faculty members in the departments Physics and Astronomy and Electrical and Computer Engineering, as well as IQC. The other authors of this work from IQC are Jean-Luc Orgiazzi, Muhammet Ali Yurtulan, PhD students, and Ron Belyansky, undergraduate research assistant. The project was carried out in collaboration with Juan Jose Garcia-Ripoll, PhD, from the Instituto de Física Fundamental in Madrid, Spain, and Borja Peropadre, PhD, from Harvard University.
Pamela Smyth | EurekAlert!
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine