Featured Research

from universities, journals, and other organizations

Faster X-ray Interferometers Due To Single-photon Interference

Date:
December 21, 2007
Source:
Physikalisch-Technische Bundesanstalt
Summary:
By means of X-ray interferometers, lengths down to the mm range can be measured with a resolution of less than one nm. The low translation velocity of the interferometers, which made their use in practice more difficult, could now be increased by a factor of 100 by exploiting the temporal correlation of singly interfering X-ray photons.

The core piece of the X-ray interferometer, made from a silicon single crystal, furnishes the lattice parameter of silicon as an utmost precisely determined length scale.
Credit: Image courtesy of Physikalisch-Technische Bundesanstalt

By means of X-ray interferometers, lengths down to the mm range can be measured with a resolution of less than one nm. The low translation velocity of the interferometers, which made their use in practice more difficult, could now be increased by a factor of 100 by exploiting the temporal correlation of singly interfering X-ray photons.

Related Articles


X-ray interferometers can measure lengths in the mm range with sub-nm resolution, whereby the almost perfect crystal grid of high-purity silicon is used as a length scale. The dimensions of any sub-m-structured samples are thereby compared with the lattice parameter of silicon (λ0~0.543... nm) which has been determined very precisely within the scope of the project for the new definition of the Avogadro constant. For metrological applications in connection with scanning probe microscopes, such measurements are of great importance.

Up to now, a further spreading of this method had, however, been impeded by the low translation velocities of only 1 nm/s to 10 nm/s. They are due to the limited intensity of typical laboratory X-ray sources: the necessary filtering of the periodic interference signal leads to a reduction in contrast which, in a classic measurement, requires a slow translation of the interferometer.

In a quantum-mechanical sense, however, interference occurs also in a strongly "diluted" stream of X-ray photons: Regarded as a wave packet, even single photons follow in their temporal impact on the detector the same probability which, in the case of sufficiently intense X-ray light, leads to the continuous signal whose period one wants to determine.

This well-known quantum-mechanical fact is now exploited for a specific purpose: if one protocols the times at which the single photons hit the detector, one can, by means of a subsequent Fourier transform of this time series, determine very precisely the frequency at which the lattice periods were passed. At constant velocity, it is then possible to reconstruct the path information, and one obtains the same information as with the classic measurement, but in a much shorter amount of time.

Thus, translation velocities of up to 1000 nm/s could be realised. This method will in future not only be used in further improved measuring arrangements for the determination of the lattice parameter of silicon, but also for other length measurements in nanotechnology.


Story Source:

The above story is based on materials provided by Physikalisch-Technische Bundesanstalt. Note: Materials may be edited for content and length.


Cite This Page:

Physikalisch-Technische Bundesanstalt. "Faster X-ray Interferometers Due To Single-photon Interference." ScienceDaily. ScienceDaily, 21 December 2007. <www.sciencedaily.com/releases/2007/12/071218101155.htm>.
Physikalisch-Technische Bundesanstalt. (2007, December 21). Faster X-ray Interferometers Due To Single-photon Interference. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2007/12/071218101155.htm
Physikalisch-Technische Bundesanstalt. "Faster X-ray Interferometers Due To Single-photon Interference." ScienceDaily. www.sciencedaily.com/releases/2007/12/071218101155.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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