Eric Sembrat's Test Bonanza

Image: 

CRA Seminar- 1:00PM **Special Time**

Abstract:

The discovery of the Higgs boson reinforces the possibility that other similar, scalar particles may exist in nature. In this talk, I will begin by discussing one such dark matter and sometime inflaton candidate, the axion.

Georgia Tech Hosts International VERITAS and CTA-US Collaboration Meetings

School of Physics Assistant Professor Nepomuk Otte hosts astrophysics researchers in the VERITAS (Very Energetic Radiation Imaging Telescope Array System) and CTA (Cherenkov Telescope Array) collaborations. Attendees are coming not only from the U.S. but also from Canada, Ireland, Germany, Italy, and Japan. 

The VERITAS collaboration operates four telescope arrays in southern Arizona. Researchers will discuss recent results obtained with the instruments and where the work is headed. Also to be discussed are some management items.

Another Eclipse Is On the Horizon for Tech Stargazers

Monday, January 29, 2018

James Sowell, director of the Georgia Tech Observatory, has good and bad news for those wanting to watch Wednesday’s total lunar eclipse.

“The good news is that this event can be safely seen with the naked eye. No eye protection is needed,” Sowell says, referring to the memorable Aug. 21, 2017, total solar eclipse, which drew thousands to Tech Green on the first day of classes last year. “Eclipses are great visual experiences.”

They are — when you can actually see them, that is. The bad news from Sowell is that Wednesday’s moments of totality will be hidden from the Tech community. “The Earth’s shadow will start crossing the moon about 6:48 a.m. EST. The moon sets at 7:30 a.m.  We can see partial aspects of the eclipse, but unfortunately, we will not get to see any of the totality.”

For those planning to rise early to see what they can of the lunar eclipse, Wednesday morning’s forecast calls for clear skies, says Sowell, who is also a senior academic professional in the School of Physics. The Georgia Tech Observatory will not be open because the field of view of its telescope “is just a small area of the moon,” he adds.

The eclipsed moon will be the second full moon in January, so it qualifies as a “blue moon,” Sowell says, although its color will not be blue. It will also be a “blood moon” because the red part of the sunlight’s spectrum will illuminate Earth’s satellite, but the redness would be visible only during totality.

The eclipse barely misses occurring when the moon’s orbit brings the moon closest to Earth. “When the moon is at its closest, it should appear a little larger in the sky.” That happens on Tuesday, Jan. 30.

Media Contact: 

Renay San Miguel 
Communications Officer
College of Sciences

Summary: 

The good news is that we don't need special eyeglasses to watch the Jan. 31, 2018, lunar eclipse. The bad news is that we won't see totality as the moon will set before it happens. 

Intro: 

The good news is that we don't need special eyeglasses to watch the Jan. 31, 2018, lunar eclipse. The bad news is that we won't see totality as the moon will set before it happens. 

Alumni: 

Binary Neutron Star Merger GW170817: A Multi-Sensory Experience of the Universe

A Frontiers in Science Panel Discussion

August 17, 2017, is a milestone date for astrophysics. For the first time, the LIGO and Virgo gravitational-wave observatories detected signals from the collision of two neutron stars. The powerful event shook space-time and produced a fireball of light and radiation from the formation of heavy elements.

Air Force Grant Enables Quantum Simulation Using Cold Atoms

Friday, January 26, 2018

In the lab of Colin Parker in the Howey Physics Building, certain atoms are cooled to ten-thousandth of a degree above absolute zero (0 kelvin). Parker accomplishes this feat with equipment laid out on a surface that is similar in size to about four eight-seat rectangular dining tables laid side by side. Cables and wires and lasers and vacuum lines crisscross the platform, keeping a few million ultracold atoms suspended in a vacuum chamber about eight cubic inches in volume.

Thus begins Parker’s adventure into the land of ultracold atomic Kondo impurities. The atoms need to get down to a millionth of a degree above 0 kelvin before Parker could start experiments to discover the nature of Kondo impurities. A three-year, $450,000 Air Force Office of Scientific Research Young Investigator Award makes possible Parker’s journey, which commenced in December 2017.

Kondo impurities are magnetic contaminants embedded in a metal crystal that cause a unique behavior as the metal cools. When electrons hit the impurity, they bounce off, the rebound sometimes accompanied by a change in the electron’s internal state. As the metal cools to lower and lower temperatures, the internal-state flipping occurs at increasing probability. Eventually, the metal cools to a point when all the electrons bouncing off the impurity undergo an internal-state flip.  

Strange things happen at ultracold temperatures, when thermal energy is removed from a system and what remains is only the intrinsic energy of the particles in it. So-called quantum systems are the subject of intense curiosity, because of the interesting materials they have yielded.

“Quantum systems have led to materials that we use, including the materials in computer hard drives,” says Parker, an assistant professor in the School of Physics. Other examples are high-temperature superconductors, which conduct electrical current without resistance at operational temperatures higher than those of traditional superconductors, and heavy fermion materials, in which electrons appear to be hundreds of times as massive as normal electrons. “It’s possible they will turn up things we can use to make maglev trains,” Parker says.

The Kondo effect refers to the formation of a cloud of electrons screening a magnetic impurity. It is known to lead to high resistivity at low temperatures. Why all these things happen is what Parker wants to find out. 

Parker will use a simulation approach to discover the inner workings of the Kondo effect. Instead of studying materials directly, Parker will use atoms to make inferences about the materials. Cesium will stand-in for the magnetic impurity, and lithium will take the role of the electrons hitting and then bouncing off the impurity.

“The advantage with atoms is that we can measure a lot of things that would be tough to measure with solid materials,” Parker says. “To measure on the time scale for an electron to move from one atom to neighbor is extremely difficult. In our system, things move more slowly and they are farther apart.” With the quantum simulation system, Parker could also easily set different experimental conditions and observe the consequent outcomes.

“We’re only just starting to get to understand how to use superconductors and other exotic quantum materials in technology,” Parker says. “Down the road, we can imagine applications in quantum computing. Another thing would be sensors. Really far out but possible, the physics we uncover could have major implications for the power grid.”

Media Contact: 

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

Summary: 

Strange things happen at ultracold temperatures, when thermal energy is removed from a system and what remains is only the intrinsic energy of the particles in it. So-called quantum systems are the subject of intense curiosity, because of the interesting materials they have yielded.

Intro: 

Strange things happen at ultracold temperatures, when thermal energy is removed from a system and what remains is only the intrinsic energy of the particles in it. So-called quantum systems are the subject of intense curiosity, because of the interesting materials they have yielded.

Alumni: 

Binary Neutron Star Merger GW170817: A Multi-sensory Experience of the Universe

A Frontiers in Science Panel Discussion

Panelists: Professors Laura Cadonati, Nepomuk Otte, and Ignacio Taboada. 

Moderator: School Chair and Professor Pablo Laguna

High-field Far-Infrared Spectroscopy of Magnetic Materials

Abstract

Many magnetic materials exhibit resonance phenomena in the far infrared frequency range, between 10- 100 cm-1 (or 0.3-3 THz). The experimental studies of these ecitations allows the determination of basic magnetic parameters, like exchange constants, magnetic anisotropy, g-factors, etc. The application of the magnetic field significantly enhances such characterization by analyzing the two-dimensional map of resonance frequencies vs magnetic field. Here I am going to show several examples of the studies:

-         Zero-field splitting in single ion magnets.

Lefton, Schatz in 2018 Innovation for All Conference

Flashpoint works closely with founders to enable them to think clearly about their businesses. It is unique in implementing startup engineering, a business creation and innovation process developed by Merrick Furst, Distinguished Professor in the College of Computing at Georgia Tech.

Pages

Subscribe to RSS - Eric Sembrat's Test Bonanza