Featured Research

from universities, journals, and other organizations

Cold atoms image microwave fields

Date:
August 10, 2010
Source:
Max Planck Institute of Quantum Optics
Summary:
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 allows for the direct and complete imaging of microwave magnetic fields with high spatial resolution.

Atoms as sensors for microwave fields. The internal-state distribution of a cloud of ultracold atoms is shown in close proximity of a microchip after applying a microwave pulse. The different pictures correspond to different field components of the microwave.
Credit: Max Riedel/Pascal Böhi/Philipp Treutlein, MPQ and LMU München

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.

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.


Story Source:

The above story is based on materials provided by Max Planck Institute of Quantum Optics. Note: Materials may be edited for content and length.


Journal Reference:

  1. Pascal Böhi, Max F. Riedel, Theodor W. Hänsch, and Philipp Treutlein. Imaging of microwave fields using ultracold atoms. Applied Physics Letters, 2010; 97 (5): 051101 DOI: 10.1063/1.3470591

Cite This Page:

Max Planck Institute of Quantum Optics. "Cold atoms image microwave fields." ScienceDaily. ScienceDaily, 10 August 2010. <www.sciencedaily.com/releases/2010/08/100803072714.htm>.
Max Planck Institute of Quantum Optics. (2010, August 10). Cold atoms image microwave fields. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2010/08/100803072714.htm
Max Planck Institute of Quantum Optics. "Cold atoms image microwave fields." ScienceDaily. www.sciencedaily.com/releases/2010/08/100803072714.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins