Light in a New Light
Creating Different Kinds of Light with Manipulable Quantum Properties
Omar Maga帽a-Loaiza observes his efficient source of spontaneous parametric down-conversion. This source uses a nonlinear crystal to produce correlated photon pairs.
Photo: Elsa Hahne/ORED
In a paper published today in Nature鈥檚 NPJ Quantum Information, Omar Maga帽a-Loaiza, assistant professor in the 海角社区 Department of Physics & Astronomy,
and his team of researchers describe a noteworthy step forward in the quantum manipulation
and control of light, which has far-reaching quantum technology applications in imaging,
simulation, metrology, computation, communication, and cryptography, among other areas.
The paper, titled 鈥淢ultiphoton quantum-state engineering using conditional measurements,鈥�
includes co-authors from the National Institute of Standards and Technology in Boulder,
Colo., institutes and universities in Mexico and Germany, as well as Chenglong You,
an 海角社区 postdoctoral researcher and member of Dr. Maga帽a-Loaiza鈥檚 experimental quantum
photonics group.
At the quantum level, light remains difficult to control for engineering purposes.
鈥淚f we鈥檙e able to control photon fluctuations and associated noise,鈥� Maga帽a-Loaiza
argued, 鈥渢hen we can make more precise measurements. This technology is new and will
change our field.鈥� Physicists all over the world are racing to develop techniques
to preserve light鈥檚 quantum properties at large enough scales for practical purposes.
While physicists can so far control the quantum properties of single photons and pairs
of photons, leading to powerful applications through entanglement and 鈥渉eralding鈥�
(wherein knowledge of one photon gives relatively certain knowledge about another,
not-yet-detected photon), Maga帽a-Loaiza鈥檚 team successfully demonstrated a method
to generate groups of photons with these same powerful properties鈥攌nown as multiphoton
states. By subtracting out some photons, Maga帽a-Loaiza said, 鈥渨e can reshape the form
of the wavepacket and artificially increase the number of photons in it.鈥� Moreover,
whereas previous scientists produced multiphoton states using multiple sources, Maga帽a-Loaiza鈥檚
team managed to build a single source to produce multiphoton packets that share similarities
with entangled lasers: a major technological achievement.
But perhaps most impressively, the publication reveals that Maga帽a-Loaiza鈥檚 team can
generate multiple kinds of light with manipulable quantum states in one single setup.
鈥淚 really think we鈥檙e doing something new, and I think people are starting to recognize
this,鈥� he said. In addition to generating single photons, they can also produce entangled
laser light and entangled natural light (i.e., sunlight) with desired properties.
鈥淚f you鈥檙e able to manipulate light at this fundamental level,鈥� Maga帽a-Loaiza said,
鈥測ou can engineer light.鈥�
Source of entangled photons. A lens is used to focus the pump beam onto the non-linear crystal, the generated entangled photons are collected by a second lens and then sent to a polarizing beam splitter. This is utilized to direct entangled photons to different ports of the source. Photons with different polarizations emerge through different output ports. The red laser in the polarizing beam splitter is utilized for alignment purposes.
Photo: Elsa Hahne/ORED
Maga帽a-Loaiza obtained his PhD in experimental quantum optics at the University of
Rochester in 2016 before becoming a research associate at the National Institute of
Standards and Technology in Boulder, Colo. He then joined the faculty at Louisiana
State University in August of 2018, where he leads the experimental quantum photonics
group. Making exciting advances in quantum metrology, the group is using sources of
entangled photons to develop multiple quantum technologies. A paper Maga帽a-Loaiza
recently co-authored with Dr. You while the latter was still a doctoral student, 鈥淢ultiphoton
quantum metrology without pre- and post-selected measurements,鈥� including contributions
from 海角社区 physicist Jonathan Dowling and several collaborators, was selected as a winner
of the Emil Wolf Outstanding Student Paper Competition this week.
More information about Maga帽a-Loaiza and his research is available on his faculty website as well as on the website for the 海角社区 . The paper, 鈥淢ultiphoton quantum-state engineering using conditional measurements,鈥� is available online in Nature's . In other news, Maga帽a-Loaiza鈥檚 former student and now postdoctoral researcher in the 海角社区 Department of Physics & Astronomy, Chenglong You, was recently named as a winner of the 2019 Emil Wolf Outstanding Student Paper Competition鈥�the first award winner from Louisiana.
Kristopher Mecholsky, Ph.D.
海角社区 Office of Research & Economic Development
225-578-7695
kmecho1@lsu.edu
Elsa Hahne
海角社区 Office of Research & Economic Development
225-578-4774
ehahne@lsu.edu