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-µm-structured samples are thereby compared with the lattice parameter of silicon (?0~0.543... 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.
Erika Schow | alfa
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences