Nav: Home

Diamonds coupled using quantum physics

April 10, 2017

Diamonds with minute flaws could play a crucial role in the future of quantum technology. For some time now, researchers at TU Wien have been studying the quantum properties of such diamonds, but only now have they succeeded in coupling the specific defects in two such diamonds with one another. This is an important prerequisite for the development of new applications, such as highly sensitive sensors and switches for quantum computers. The results of the research will now be published in the journal Physical Review Letters.

In search of a suitable quantum system

"Unfortunately, quantum states are very fragile and decay very quickly", explains Johannes Majer, head of the hybrid quantum research group, based at the Institute of Atomic and Subatomic Physics at TU Wien. For this reason, in-depth research is being carried out with the aim of finding quantum systems that can be used for technical applications. Even though there are some promising candidates with particular advantages, up until now there has been no system that fulfils all of the requirements simultaneously.

"Diamonds with very specific defects are one potential candidate for making quantum computers a reality", says Johannes Majer. A pure diamond is made up solely of carbon atoms. In some diamonds, however, there can be points where there is a nitrogen atom instead of a carbon atom and neighbouring this, within the atomic structure of the diamond, there is an anomaly where there is no atom at all - this is referred to as a 'vacancy'. This defect, consisting of the nitrogen atom and vacancy, forms a quantum system with a very long-lasting state, making diamonds with these particular flaws ideally suited to quantum experiments.

It all depends on the coupling

One important pre-requisite for many quantum technological applications is indeed the ability to couple such quantum systems together, which up until now has scarcely been possible for diamond systems. "The interaction between two such nitrogen-vacancy defects is extremely weak and only has a reach of around 10 nanometres", says Majer.

However, this feat has now been achieved; albeit with the help of a superconducting quantum chip that produces microwave radiation. For a number of years now, the team at TU Wien has been investigating how diamonds can be manipulated with the help of microwaves: "billions of nitrogen-vacancy defects in diamonds are coupled collectively with a microwave field", says Majer. "In this way, the quantum state of the diamonds can be manipulated and read out."

Now, the team has succeeded in taking the next step: they were able to couple two different diamonds, one at each end of the chip, thus producing an interaction between the two diamonds. "This interaction is mediated by the microwave resonator in the chip in between; here, the resonator plays a similar role to that of a data bus in a regular computer", says Johannes Majer.

The coupling between the two diamonds can be switched on and off selectively: "the two diamonds are rotated against each other at a certain angle", reports Thomas Astner, the lead author of the current work. "Additionally, a magnetic field is applied, with the direction playing a decisive role: if both diamonds are aligned at the same angle within the magnetic field, then they can be coupled using quantum physics. With other magnetic field directions, it is possible to investigate the individual diamonds without coupling". The first steps in the experiment were taken by Noomi Peterschofsky as part of her undergraduate thesis. Thomas Astner and Stefan Nevlacsil subsequently succeeded in demonstrating the coupling of the diamonds in an experiment as part of their Master's thesis.
-end-
Original publication: T. Astner et al., Phys. Rev. Lett. 118, 140502 https://doi.org/10.1103/PhysRevLett.118.140502

Photo download https://www.tuwien.ac.at/dle/pr/aktuelles/downloads/2017/quantendiamanten

Further information:

Dr. Johannes Majer
Institute of Atomic and Subatomic Physics
TU Wien
Stadionalle 2, 1020 Vienna
T: +43-699-10253808
johannes.majer@tuwien.ac.at

Vienna University of Technology

Related Magnetic Field Articles:

Scholes finds novel magnetic field effect in diamagnetic molecules
The Princeton University Department of Chemistry publishes research this week proving that an applied magnetic field will interact with the electronic structure of weakly magnetic, or diamagnetic, molecules to induce a magnetic-field effect that, to their knowledge, has never before been documented.
Origins of Earth's magnetic field remain a mystery
The existence of a magnetic field beyond 3.5 billion years ago is still up for debate.
New research provides evidence of strong early magnetic field around Earth
New research from the University of Rochester provides evidence that the magnetic field that first formed around Earth was even stronger than scientists previously believed.
Massive photons in an artificial magnetic field
An international research collaboration from Poland, the UK and Russia has created a two-dimensional system -- a thin optical cavity filled with liquid crystal -- in which they trapped photons.
Adhesive which debonds in magnetic field could reduce landfill waste
Researchers at the University of Sussex have developed a glue which can unstick when placed in a magnetic field, meaning products otherwise destined for landfill, could now be dismantled and recycled at the end of their life.
Earth's last magnetic field reversal took far longer than once thought
Every several hundred thousand years or so, Earth's magnetic field dramatically shifts and reverses its polarity.
A new rare metals alloy can change shape in the magnetic field
Scientists developed multifunctional metal alloys that emit and absorb heat at the same time and change their size and volume under the influence of a magnetic field.
Physicists studied the influence of magnetic field on thin film structures
A team of scientists from Immanuel Kant Baltic Federal University together with their colleagues from Russia, Japan, and Australia studied the influence of inhomogeneity of magnetic field applied during the fabrication process of thin-film structures made from nickel-iron and iridium-manganese alloys, on their properties.
'Magnetic topological insulator' makes its own magnetic field
A team of U.S. and Korean physicists has found the first evidence of a two-dimensional material that can become a magnetic topological insulator even when it is not placed in a magnetic field.
Scientists develop a new way to remotely measure Earth's magnetic field
By zapping a layer of meteor residue in the atmosphere with ground-based lasers, scientists in the US, Canada and Europe get a new view of Earth's magnetic field.
More Magnetic Field News and Magnetic Field Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Uncounted
First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at Radiolab.org/donate.