Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cold atoms image microwave fields

03.08.2010
Using clouds of ultracold atoms MPQ-LMU team of scientists makes microwave fields visible.

Microwaves are an essential part of modern communication technology. Mobile phones and laptops, for example, are equipped with integrated microwave circuits for wireless communication. Sophisticated techniques for measurement and characterization of microwave fields are an essential tool for the development of such circuits.

A novel technique developed by a group of scientists around Prof. Theodor W. Hänsch (Max Planck Institute of Quantum Optics and Ludwig-Maximilians-Universität Munich (LMU)) and Prof. Philipp Treutlein (University of Basel) allows for the direct and complete imaging of microwave magnetic fields with high spatial resolution. In this technique, clouds of ultracold atoms serve as sensors for the microwave field. The technique is described in the cover story of the current issue of Applied Physics Letters (Appl. Phys. Lett. 97, (2010)).

Modern wireless communication is based on the transmission of information through radio waves and microwaves. Integrated microwave circuits in devices such as mobile phones and computer laptops decode and process this information. Computer simulations play an important role in the development of these circuits. However, because of the large number of components in modern integrated circuits, such simulations have to rely on approximations and are not always reliable. Therefore, measurements are required to test the circuits and to verify their performance.

To enable efficient testing and specific improvement, one would ideally like to measure all components of the microwave field directly and with very high spatial resolution. In existing techniques for measuring microwave fields, the field distribution has to be scanned point-by-point, so that this kind of data acquisition is slow. Moreover, most techniques only allow for a measurement of the amplitudes, but not of the phases of the microwave field. Furthermore, macroscopic probe heads used for the measurement can distort the microwave field and result in poor spatial resolution.

Scientists at the Max Planck Institute of Quantum Optics, the LMU Munich and the University of Basel have now demonstrated a new technique for the imaging of microwave magnetic fields. As microwave field sensors, they use small clouds of ultracold atoms that hade been laser-cooled to a temperature of a few millionths of a degree above absolute zero. At these temperatures, the atoms obey the laws of quantum physics. Their quantum state is very sensitive to externally applied electromagnetic fields, which makes them ideal sensors. For the measurement, the atoms are positioned at the desired location above the microwave circuit with the help of static magnetic fields, and subsequently the microwave field is turned on.

„The internal state of the atoms changes if a microwave field is applied“, Pascal Böhi explains, who co-developed the technique as part of this doctoral thesis. „We can image this change of internal state with a CCD camera with high spatial resolution. The stronger the microwave field at a given position, the faster the rate of change we observe.” A unique feature of the new method is that it does not require the microwave field to be scanned point-by-point. Rather, a fully two-dimensional image of one component of the microwave field can be recorded in a single shot. This increases the data acquisition rate dramatically. In addition, the technique allows not only for a reconstruction of the amplitudes, but also of the phases of the microwave field components. As the atoms are truly microscopic objects, they do not distort the microwave circuit to be characterized, in contrast to macroscopic probe heads. The new method works for various frequencies in the gigahertz range.

„We have successfully demonstrated the new technique in our lab. Quite naturally, further development is necessary before it could be used in commercial applications“, says Philipp Treutlein, the leader of the project. However, a very compact and portable setup for experiments with ultracold atoms was recently built and could be of interest for such applications. The setup itself is at room temperature, but the atoms trapped inside are cooled within a few seconds with the help of laser light. Key components of such systems are now commercially available. Because of the potential for applications, the researchers have submitted a patent application describing the new technique. Philipp Treutlein

Original publication:
Pascal Böhi, Max F. Riedel, Theodor W. Hänsch, and Philipp Treutlein
Imaging of microwave fields using ultracold atoms
Applied Physics Letters 97, (2010), doi:10.1063/1.3470591
Contact:
Prof. Dr. Philipp Treutlein
Max Planck Institute of Quantum Optics
and LMU Munich, Faculty of Physics
Schellingstr. 4/III, 80799 Munich
Phone: +49-(0)89-2180-3937
e-mail: treutlein@lmu.de
www.munichatomchip.de
University of Basel, Department of Physics
Klingelbergstrasse 82, CH-4056 Basel
e-mail: philipp.treutlein@unibas.ch
www.atom.physik.unibas.ch
Prof. Dr. Theodor W. Hänsch
Chair of Experimental Physics, LMU Munich
Director at the Max Planck Institute of Quantum Optics
Hans-Kopfermann-Str. 1, 85748 Garching
Phone: +49-(0)89-32905-702/712
e-mail: t.w.haensch@mpq.mpg.de
Dipl.-Phys. Pascal Böhi
Max Planck Institute of Quantum Optics
and LMU Munich, Faculty of Physics
Schellingstr. 4/III, 80799 Munich
Phone: +49-(0)89-2180-3703
e-mail: pascal.boehi@physik.lmu.de
Dr. Olivia Meyer-Streng
Press & Public Relations
Max Planck Institute of Quantum Optics
Phone: +49 - 89 / 32905 - 213
e-mail: olivia.meyer-streng@mpq.mpg.de

Dr. Olivia Meyer-Streng | idw
Further information:
http://www.mpq.mpg.de

More articles from Physics and Astronomy:

nachricht Scientists reach back in time to discover some of the most power-packed galaxies
28.02.2017 | Clemson University

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

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: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Scientists reach back in time to discover some of the most power-packed galaxies

28.02.2017 | Physics and Astronomy

Nano 'sandwich' offers unique properties

28.02.2017 | Materials Sciences

Light beam replaces blood test during heart surgery

28.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>