Nav: Home

Breaking the symmetry in the quantum realm

May 31, 2019

For the first time, researchers have observed a break in a single quantum system. The observation--and how they made the observation--has potential implications for physics beyond the standard understanding of how quantum particles interact to produce matter and allow the world to function as we know it.

The researchers published their results on May 31st, in the journal Science.

Called Parity-Time (PT) Symmetry, the mathematical term describes the properties of a quantum system--the evolution of time for a quantum particle, as well as if the particle is even or odd. Whether the particle moves forward or backward in time, the state of oddness or evenness remains the same in the balanced system. When the parity changes, the balance of system -- the symmetry of the system -- breaks.

In order to better understand quantum interactions and develop next-generation devices, researchers must be able to control the symmetry of systems. If they can break the symmetry, they could manipulate the spin state of the quantum particles as they interact, resulting in controlled and predicted outcomes.

"Our work is about that quantum control," said Yang Wu, an author on the paper and a PhD student in the Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics at the University of Science and Technology of China. Wu is also a member of the Chinese Academy of Sciences Key Laboratory of Microscale Magnetic Resonance.

Wu, his PhD supervisor Rong and colleagues used a nitrogen-vacancy center in a diamond as their platform. The nitrogen atom with an extra electron, surrounded by carbon atoms, creates the perfect capsule to further investigate the PT symmetry of the electron. The electron is a single-spin system, meaning the researchers can manipulate the entire system just by changing the evolution of the electron spin state.

Through what Wu and Rong call a dilation method, the researchers applied a magnetic field to the axis of the nitrogen-vacancy center, pulling the electron into a state of excitability. They then applied oscillating microwave pulses, changing the parity and time direction of the system and causing it to break and decay with time.

"Due to the universality of our dilation method and the highly controllability of our platform, this work paves the way to study experimentally some new physical phenomena related to PT symmetry," Wu said.

Corresponding authors Jiangfeng Du and Xing Rong, professors with the Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics at the University of Science and Technology of China, were in agreement.

"The information extracted from such dynamics extends and deepens the understanding of quantum physics," said Du, who is also an academician of the Chinese Academy of Sciences. "The work opens the door to the study of exotic physics with non-classical quantum systems."

The other authors include Wenquan Liu, Jianpei Geng, Xingrui Song, Xiangyu Ye, Chang-Kui Duan and Xing Rong. All of the authors are affiliated with the Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics at the University of Science and Technology of China. Liu, Ye, Duan, Rong and Du are also affiliated with both the University's CAS Key Laboratory of Microscale Magnetic Resonance, and the University's Synergetic Innovation Center of Quantum Information and Quantum Physics.
-end-
Professor Xing Rong is available for interviews in English and Chinese.

Media contact:
Xing Rong
Department of Modern Physics
University of Science and Technology of China (USTC)
xrong@ustc.edu.cn

University of Science and Technology of China

Related Quantum Physics Articles:

Quantum physics: On the way to quantum networks
Physicists at Ludwig-Maximilians-Universitaet (LMU) in Munich, together with colleagues at Saarland University, have successfully demonstrated the transport of an entangled state between an atom and a photon via an optic fiber over a distance of up to 20 km -- thus setting a new record.
Quantum physics: Controlled experiment observes self-organized criticality
Researchers from Cologne, Heidelberg, Strasbourg and California have observed important characteristics of complex systems in a lab experiment.
A platform for stable quantum computing, a playground for exotic physics
Harvard University researchers have demonstrated the first material that can have both strongly correlated electron interactions and topological properties, which not only paves the way for more stable quantum computing but also an entirely new platform to explore the wild world of exotic physics.
A new quantum data classification protocol brings us nearer to a future 'quantum internet'
A new protocol created by researchers at the Universitat Autònoma de Barcelona sorts and classifies quantum data by the state in which they were prepared, with more efficiency than the equivalent classical algorithm.
Quantum physics: Ménage à trois photon-style
When two photons become entangled, the quantum state of the first will correlate perfectly with the quantum state of the second.
Quantum physics -- Simulating fundamental interactions with ultracold atoms
An international team of physicists succeeded in precisely engineering key ingredients to simulate a specific lattice gauge theory using ultracold atoms in optical lattices.
A key piece to understanding how quantum gravity affects low-energy physics
In a new study, led by researchers from SISSA (Scuola Internazionale Superiore di Studi Avanzati), the Complutense University of Madrid and the University of Waterloo, a solid theoretical framework is provided to discuss modifications to the Unruh effect caused by the microstructure of space-time.
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Quantum physics and origami for the ultimate get-well card
The bizarre optical properties of tiny metal particles -- smaller than light waves -- can be captured on paper to detect even a single target molecule in a test sample.
Can artificial intelligence solve the mysteries of quantum physics?
A new study published in Physical Review Letters by Prof.
More Quantum Physics News and Quantum Physics 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

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#555 Coronavirus
It's everywhere, and it felt disingenuous for us here at Science for the People to avoid it, so here is our episode on Coronavirus. It's ok to give this one a skip if this isn't what you want to listen to right now. Check out the links below for other great podcasts mentioned in the intro. Host Rachelle Saunders gets us up to date on what the Coronavirus is, how it spreads, and what we know and don't know with Dr Jason Kindrachuk, Assistant Professor in the Department of Medical Microbiology and infectious diseases at the University of Manitoba. And...
Now Playing: Radiolab

Dispatch 1: Numbers
In a recent Radiolab group huddle, with coronavirus unraveling around us, the team found themselves grappling with all the numbers connected to COVID-19. Our new found 6 foot bubbles of personal space. Three percent mortality rate (or 1, or 2, or 4). 7,000 cases (now, much much more). So in the wake of that meeting, we reflect on the onslaught of numbers - what they reveal, and what they hide.  Support Radiolab today at Radiolab.org/donate.