Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First single-photon source that works with atomic gases at room temperature

29.10.2018

Researchers of the Center for Integrated Quantum Science and Technology IQST at the 5th Institute of Physics at the University of Stuttgart (Head: Prof. Tilman Pfau) have developed a novel, promising variant of a light source for the smallest possible energy packages - a so-called single-photon source. Their work has been published in the latest issue of the journal Science.*

A photon is the smallest conceivable amount of light. Classical light sources such as light bulbs or the sun emit many photons simultaneously, in random order. A single photon source on the other hand, emits only a single photon in a controlled way.


Rubidium atoms are excited to their Rydberg states in a glass cell at room temperature. The volume between the glass plates is so thin that colored interference rings are visible to the naked eye.

Universität Stuttgart/Max Kovalenko

Such light sources have been known for about 20 years, but the various approaches (e.g. quantum dots or nitrogen defect centers in diamonds) are hot topics in research worldwide. The special feature of this new light source is that it can be operated without expensive cooling methods that need liquid gases or lasers.

The secret lies in the glass cell

The Stuttgart-based single-photon source works with atomic gases at room temperature for the first time. The secret lies in a credit card-sized glass cell filled with a vapor of rubidium atoms. The quantum character of the generated light is based on strong interactions between the individual atoms in the vapor cell. In order for the atoms to interact strongly, they are brought into highly excited Rydberg states by laser light.

These are states in which the outermost electron of each atom is particularly far away from the rest of the atom. Due to their enormous size, the interaction between two Rydberg atoms is very strong. A single Rydberg excitation does not allow another Rydberg atom in its vicinity and thus blocks the entire atomic cloud.

"Since the atoms are trapped in a microscopically small glass cell, only one Rydberg excitation can ever occur in this cell - no matter how many atoms are trapped in the cell," explains Fabian Ripka, a PhD student at the 5th Institute of Physics at the University of Stuttgart. When this single excitation subsides again, a single quantum of light - a photon - is emitted. The Stuttgart researchers can specifically control the Rydberg excitation and the emission of the photon.

Individual photons already play an important role in quantum technology applications. Since they cannot be copied unnoticed, they are suitable, for example, for tap-proof quantum communication and are used in quantum cryptography. Prof. Tilman Pfau also sees great potential for single photons in so-called quantum computers. "In photonic networks, single-photon sources will be an essential component for performing quantum algorithms," says the quantum physicist.

About IQST

The Center for Integrated Quantum Science and Technology IQST, a center for quantum sciences funded by the state of Baden-Württemberg, is a consortium of the Universities of Stuttgart and Ulm and the Max Planck Institute for Solid State Research in Stuttgart. The aim of the center is to promote synergies between physics and related natural and engineering sciences and to represent quantum science from the basics to technological applications.

Researchers at the 5th Physics Institute led by Prof. Tilman Pfau are investigating the quantum properties of atoms in the IQST and are trying to control them in a targeted way in their search for new states of matter or possible applications for quantum information technology and quantum optics.

Wissenschaftliche Ansprechpartner:

Prof. Dr. Tilman Pfau, Universität Stuttgart, Tel.: +49 (0)711/685 64820, Mail: t.pfau@physik.uni-stuttgart.de

Originalpublikation:

Fabian Ripka, Harald Kübler, Robert Löw, Tilman Pfau: A room-temperature single-photon source based on strongly interacting Rydberg atoms, Science from 26.10.2018, Vol. 362, Issue 6413, pp. 446-449, DOI: 10.1126/science.aau1949

Andrea Mayer-Grenu | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-stuttgart.de/

More articles from Physics and Astronomy:

nachricht Appreciating the classical elegance of time crystals
20.09.2019 | ETH Zurich Department of Physics

nachricht 'Nanochains' could increase battery capacity, cut charging time
20.09.2019 | Purdue University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: 'Nanochains' could increase battery capacity, cut charging time

How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.

Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...

Im Focus: Stevens team closes in on 'holy grail' of room temperature quantum computing chips

Photons interact on chip-based system with unprecedented efficiency

To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

 
Latest News

Quality control in immune communication: Chaperones detect immature signaling molecules in the immune system

20.09.2019 | Life Sciences

Moderately Common Plants Show Highest Relative Losses

20.09.2019 | Life Sciences

The Fluid Fingerprint of Hurricanes

20.09.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>