Now, pushing the regime of the very cold into the very small, a research team from the National Institute of Standards and Technology (NIST), the University of Maryland, Janis Research Company, Inc., and Seoul National University, has designed and built the most advanced ultra-low temperature scanning probe microscope (ULTSPM) in the world.
Detailed in a recent paper,* the ULTSPM operates at lower temperatures and higher magnetic fields than any other similar microscope, capabilities that enable the device to resolve energy levels separated by as small as 1 millionth of an electron volt. This extraordinary resolution has already resulted in the discovery of new physics (see "Puzzling New Physics from Graphene Quartet's Quantum Harmonies").
"To get these kinds of measurements, you need to combine coarse and extremely fine movement (the mechanical positioning of a probe tip about two atoms' distance from the sample surface), ultra-high vacuum, cryogenics and vibration isolation," says NIST Fellow Joseph Stroscio, one of the device's co-creators. "We designed this instrument to achieve superlative levels of performance, which, in turn, requires achieving nearly the ultimate in environmental control."
The NIST team had to overcome many technical challenges to achieve this level of precision and sensitivity, according to Young Jae Song, a postdoctoral researcher who helped develop the instrument at NIST.
Past designs used mechanical systems to move the probe tip that did not work over a wide range of temperatures. Researchers overcame this by creating piezoelectric actuators that expand with atomic scale precision when voltage is applied.
For vibration control, the group built the ULTSPM facility on top of a separate 110-ton concrete block buffered by six computer-controlled air springs. The ULTSPM, itself, sits on a 6-ton granite table, isolated from the concrete block by another set of computer-controlled air springs.
To achieve the ULTSPM's ultra low operating temperature of 10 millikelvins, the team designed a low noise dilution refrigerator to supplement the device's chilly 3-meter deep, 250-liter liquid helium bath. Because electromagnetic radiation entering through wires and cables can heat up the microscope, the ULTSPM lab is nested inside a separate, electromagnetically shielded room.
In order to ready new samples and probes without disturbing ongoing measurements, experimenters built a vacuum-sealed "railroad" system that they can disconnect from the chamber.
"The ability to create these kinds of experimental conditions opens up a whole new frontier in nanoscale physics," says Robert Celotta, founding director of the NIST Center for Nanoscale Science and Technology. "This instrument has been five years in the making, and we can't help but be excited about all the discoveries waiting to be made."
* Y. Song, A. Otte, V. Shvarts, Z. Zhao, Y. Kuk, S. Blankenship, A. Band, F. Hess and J. Stroscio. A 10 mK scanning probe microscopy facility. Review of Scientific Instruments. In press.
Mark Esser | Newswise Science News
New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center
Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research