Researchers at Chalmers University of Technology are first to show the use of sound to communicate with an artificial atom. They can thereby demonstrate phenomena from quantum physics with sound taking on the role of light. The results are published by the journal Science.
The interaction between atoms and light is well known and has been studied extensively in the field of quantum optics. However, to achieve the same kind of interaction with sound waves has been a more challenging undertaking. The Chalmers researchers have now succeeded in making acoustic waves couple to an artificial atom. The study was done in collaboration between experimental and theoretical physicists.
On the right, an artificial atom generates sound waves consisting of ripples on the surface of a solid. The sound, known as a surface acoustic wave (SAW) is picked up on the left by a "microphone" composed of interlaced metal fingers. According to theory, the sound consists of a stream of quantum particles, the weakest whisper physically possible. The illustration is not to scale. Credit: Philip Krantz, Krantz NanoArt.
"We have opened a new door into the quantum world by talking and listening to atoms", says Per Delsing, head of the experimental research group. "Our long term goal is to harness quantum physics so that we can benefit from its laws, for example in extremely fast computers. We do this by making electrical circuits which obey quantum laws, that we can control and study."
An artificial atom is an example of such a quantum electrical circuit. Just like a regular atom, it can be charged up with energy which it subsequently emits in the form of a particle. This is usually a particle of light, but the atom in the Chalmers experiment is instead designed to both emit and absorb energy in the form of sound.
"According to the theory, the sound from the atom is divided into quantum particles", says Martin Gustafsson, the article's first author. "Such a particle is the weakest sound that can be detected."
Since sound moves much slower than light, the acoustic atom opens entire new possibilities for taking control over quantum phenomena.
"Due to the slow speed of sound, we will have time to control the quantum particles while they travel" says Martin Gustafsson. "This is difficult to achieve with light, which moves 100,000 times more quickly."
The low speed of sound also implies that it has a short wavelength compared to light. An atom that interacts with light waves is always much smaller than the wavelength. However, compared to the wavelength of sound, the atom can be much larger, which means that its properties can be better controlled. For example, one can design the atom to couple only to certain acoustic frequencies or make the interaction with the sound extremely strong.
The frequency used in the experiment is 4.8 gigahertz, close to the microwave frequencies common in modern wireless networks. In musical terms, this corresponds approximately to a D28, about 20 octaves above the highest note on a grand piano.
At such high frequencies, the wavelength of the sound becomes short enough that it can be guided along the surface of a microchip. On the same chip, the researchers have placed an artificial atom, which is 0.01 millimeters long and made of a superconducting material.
The paper Propagating phonons coupled to an artificial atom is published online by the journal Science, at the Science Express web site.
For more information, please contact:
Martin Gustafsson +46 70 745 9955 email@example.com
Göran Johansson +46 73 060 7338 firstname.lastname@example.org
Per Delsing +46 70 308 8317 email@example.com
Additional details about the research:
The sample that the researchers use is made on a substrate of gallium arsenide (GaAs) and contains two important parts. The first one is the superconducting circuit that constitutes the artificial atom. Circuits of this kind can also be used as qubits, the building blocks of a quantum computer. The other essential component is known as an interdigital transducer (IDT). The IDT converts electrical microwaves to sound and vice versa. The sound used in the experiment has the form of surface acoustic waves (SAWs) which appear as ripples on the surface of a solid. The experiments are performed at very low temperatures, near absolute zero (20 millikelvin), so that energy in the form of heat does not disturb the atom.
The theoretical research group, led by Göran Johansson, recently published a paper on how the acoustic atom functions:
The research was funded by the Swedish Research Council, the Knut and Alice Wallenberg Foundation, the European Research Council and the Wenner-Gren Foundations.
Johanna Wilde | idw - Informationsdienst Wissenschaft
NASA laser communications to provide Orion faster connections
30.03.2017 | NASA/Goddard Space Flight Center
Pinball at the atomic level
30.03.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering