Home > Press > Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices
Scientists at the Centre for Quantum Technologies at the National University of Singapore have shown that a photon's shape affects how it is absorbed by a single atom. This artist's illustration is not to scale: in the experiment the photons are some 4 meters long, while the atom is less than a nanometer wide. CREDIT Timothy Yeo / Centre for Quantum Technologies, National University of Singapore |
Abstract:
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 you're looking at. Some photons reflect off, reaching your eyes. Others get absorbed. The main decider of which happens is the photon's energy - its colour.
But look closely at the moment that light meets matter, and there's more to be discovered. Scientists at the Centre for Quantum Technologies (CQT) at the National University of Singapore have just shown that a photon's shape also affects how it is absorbed by a single atom.
We don't often think of photons as being spread out in time and space and thus having a shape, but the ones in this experiment were some four metres long. Christian Kurtsiefer, Principal Investigator at CQT, and his team have learned to shape these photons with extreme precision.
For the research, published 29 November in Nature Communications, the team worked with Rubidium atoms and infrared photons. They shone the photons one at a time onto a single atom.
"Our experiments look at the most fundamental interaction between matter and light" says Victor Leong, for whom the work contributed to a PhD degree.
A four-metre photon takes about 13 nanoseconds to pass the atom. Every time a photon was sent towards the atom, the team watched to see if and when the atom got excited. By noting the excitation times and collecting them together, the researchers could map the probability of the atom absorbing the photon as a function of time.
The team tested two different photon shapes - one rising in brightness, the other decaying. Hundreds of millions of measurements made over 1500 hours showed that the overall probability that a single Rubidium atom would absorb a single photon of either type was just over 4%. However, when the team looked at the process on nanoscale timeframes, they saw that the probability of absorption at each moment depends on the photon's shape.
The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail.
Researchers had expected atoms might prefer to soak up the rising photons. That's because of what happens naturally when an excited atom decays. Then, the atom spits out a decaying photon. Imagine running the process backwards - the equations say it should look the same - and the atom would arrive with rising brightness. "Our choice of photon shape was inspired by the time symmetry of quantum mechanics," says coauthor Matthias Steiner.
The work also builds understanding for technologies that rely on light-matter interactions. Some proposals for quantum technologies such as communication networks, sensors and computers require that a photon writes information into an atom by being absorbed. The photon knocks the atom into an excited state. To build reliable devices, scientists will need to control the interaction. "You can only engineer what you can understand," says coauthor Alessandro Cerč.
This work was supported by the Ministry of Education in Singapore (AcRF Tier 1) and the National Research Foundation, Prime Minister's office (partly under grant no NRF-CRP12-2013-03). Matthias Steiner acknowledges support by the Lee Kuan Yew Postdoctoral Fellowship.
####
For more information, please click here
Contacts:
Jenny Hogan
Researcher contacts:
Alessandro Cerč
Senior Research Fellow, Centre for Quantum Technologies, National University of Singapore
+65 6516 8454
Matthias Steiner
Lee Kuan Yew Research Fellow, Centre for Quantum Technologies, National University of Singapore
Copyright © Centre for Quantum Technologies (CQT) at the National University of Singapore
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Related News Press |
Physics
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
News and information
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Quantum Physics
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Quantum communication
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Wireless/telecommunications/RF/Antennas/Microwaves
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Govt.-Legislation/Regulation/Funding/Policy
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Possible Futures
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chip Technology
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Quantum Computing
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Optical computing/Photonic computing
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Sensors
Discoveries
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
New micromaterial releases nanoparticles that selectively destroy cancer cells April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
Announcements
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
Photonics/Optics/Lasers
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Quantum nanoscience
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
Bridging light and electrons January 12th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||