Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


First on-chip nanoscale optical quantum memory developed


Smallest-yet optical quantum memory device is a storage medium for optical quantum networks with the potential to be scaled up for commercial use

For the first time, an international team led by engineers at Caltech has developed a computer chip with nanoscale optical quantum memory.

Artist's representation of the quantum memory device.

Credit: Ella Maru Studio

Usage Restrictions: For use in news stories only

Quantum memory stores information in a similar fashion to the way traditional computer memory does, but on individual quantum particles--in this case, photons of light. This allows it to take advantage of the peculiar features of quantum mechanics (such as superposition, in which a quantum element can exist in two distinct states simultaneously) to store data more efficiently and securely.

"Such a device is an essential component for the future development of optical quantum networks that could be used to transmit quantum information," says Andrei Faraon (BS '04), assistant professor of applied physics and materials science in the Division of Engineering and Applied Science at Caltech, and the corresponding author of a paper describing the new chip.

The study appeared online ahead of publication by Science magazine on August 31.

"This technology not only leads to extreme miniaturization of quantum memory devices, it also enables better control of the interactions between individual photons and atoms," says Tian Zhong, lead author of the study and a Caltech postdoctoral scholar. Zhong is also an acting assistant professor of molecular engineering at the University of Chicago, where he will set up a laboratory to develop quantum photonic technologies in March 2018.

The use of individual photons to store and transmit data has long been a goal of engineers and physicists because of their potential to carry information reliably and securely. Because photons lack charge and mass, they can be transmitted across a fiber optic network with minimal interactions with other particles.

The new quantum memory chip is analogous to a traditional memory chip in a computer. Both store information in a binary code. With traditional memory, information is stored by flipping billions of tiny electronic switches either on or off, representing either a 1 or a 0. That 1 or 0 is known as a bit. By contrast, quantum memory stores information via the quantum properties of individual elementary particles (in this case, a light particle). A fundamental characteristic of those quantum properties--which include polarization and orbital angular momentum--is that they can exist in multiple states at the same time. This means that a quantum bit (known as a qubit) can represent a 1 and a 0 at the same time.

To store photons, Faraon's team created memory modules using optical cavities made from crystals doped with rare-earth ions. Each memory module is like a miniature racetrack, measuring just 700 nanometers wide by 15 microns long--on the scale of a red blood cell. Each module was cooled to about 0.5 Kelvin--just above Absolute Zero (0 Kelvin, or -273.15 Celsius)--and then a heavily filtered laser pumped single photons into the modules. Each photon was absorbed efficiently by the rare-earth ions with the help of the cavity.

The photons were released 75 nanoseconds later, and checked to see whether they had faithfully retained the information recorded on them. Ninety-seven percent of the time, they had, Faraon says.

Next, the team plans to extend the time that the memory can store information, as well as its efficiency. To create a viable quantum network that sends information over hundreds of kilometers, the memory will need to accurately store data for at least one millisecond. The team also plans to work on ways to integrate the quantum memory into more complex circuits, taking the first steps toward deploying this technology in quantum networks.


The study is titled "Nanophotonic rare-earth quantum memory with optically controlled retrieval." Other Caltech coauthors include postdoctoral researcher John G. Bartholomew; graduate students Jonathan M. Kindem (MS '17), Jake Rochman, and Ioana Craiciu (MS '17); and former graduate student Evan Miyazono (MS '15, PhD '17). Additional authors are from the University of Verona in Italy; the University of Parma in Italy; the National Institute of Standards and Technology in Colorado; and the Jet Propulsion Laboratory, which is managed for NASA by Caltech. This research was funded by the National Science Foundation, the Air Force Office of Scientific Research, and the Defense Advanced Research Projects Agency.

Media Contact

Robert Perkins


Robert Perkins | EurekAlert!

Further reports about: MS individual photons nanoscale photons quantum memory

More articles from Information Technology:

nachricht Next Generation Cryptography
20.03.2018 | Fraunhofer-Institut für Sichere Informationstechnologie SIT

nachricht TIB’s Visual Analytics Research Group to develop methods for person detection and visualisation
19.03.2018 | Technische Informationsbibliothek (TIB)

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>