June 1, 2015
Seeing a Single Photon, Novel Exoplanet Search, Developing a Quantum Network in Space and More at 2015 DAMOP Meeting
COLLEGE PARK, MD – The American Physical Society's 2015 Division of Atomic, Molecular and Optical Physics (DAMOP) meeting focuses on fundamental research on atoms, simple molecules, electrons and light, and their interactions. The meeting will take place June 8–12, 2015 at the Hyatt Regency Columbus and the Greater Columbus Convention Center in Columbus, Ohio.
Meeting details, including the complete meeting schedule, are available at the DAMOP 2015 Meeting website.
FINDING VENUS AND SEARCHING FOR EXOPLANETS
Thursday, June 11, 8:48 AM, Room: Franklin CD
Looking directly at Venus isn’t the only way to tell that it’s there. It’s also now possible to measure the relative motion of the Earth and Sun so precisely that physicists can use the measurement to find Venus, and eventually to find Earth-like exoplanets around distant stars. David Phillips (Harvard-Smithsonian Center for Astrophysics) and collaborators have managed the ultrasensitive measurements using a device called a laser frequency comb that allows an astronomical spectrograph to detect minute changes in the light coming from the sun. The changes they looked for result from the Doppler Effect, which causes the frequencies of signals to shift when objects move toward or away from each other. Many people are familiar with the rising and falling pitch of a passing train. In the same way, light from the sun rises in frequency as the Earth and Sun move closer together, and falls in frequency when they move farther apart. As Venus goes along its orbit, it causes the Sun to wobble a very tiny amount at speeds of about 9 centimeters per second, roughly as fast as a cruising Giant Tortoise. As impressive as the measurement is, it’s still just a precursor to the researchers’ ultimate goal - to search for the wobble generated by Earth-like planets orbiting other stars. Wobbling stars have revealed the presence of large exoplanets, but the system Phillips will present is capable of detecting planets comparable to our own. Studying the Sun with the frequency comb and astronomical spectrograph could lead to new insights about the Sun’s internal structure as well, but Phillips and collaborators are chiefly focused on planet hunting for the time being.
CAN YOU SEE A SINGLE PHOTON?
Wednesday, June 10, 2:00 PM, Room: Delaware CD
Human vision is very sensitive. Researchers already know that we can see signals consisting of only a few photons, but the precise lower limit isn't known. It may be that we can see the light of a single photon. Rebecca Holmes and colleagues at the University of Illinois are out to find the answer with a source that can provide a single photon at a time. Human trials so far seem to suggest that we might spot a single photon from time to time, but the researchers expect that it will take many thousands more tests to know for sure. The system will also help us to understand better how our optical systems process light. In another year or two, the researchers hope to begin studying the way humans perceive quantum phenomena that can be produced with photons. At that point, we may be able to understand what quantum entanglement and superposition look like to the human eye.
TELEPORTING INFORMATION FROM SPACE
Wednesday, June 10, 9:12 AM, Room: Delaware CD
Star Trek fans, take heart: we may not yet be able to teleport humans but some physicists are working toward eventually teleporting information from space. Trent Graham (University of Illinois at Urbana-Champaign) and colleagues are assembling an experimental system that relies on a novel variant of teleportation to transmit quantum information, potentially over long distances. Quantum teleportation involves quantum mechanically entangled objects (in this case, photons) that essentially act as a single object. The entanglement allows quantum information to be transported from one entangled object to its partner by only sending a few classical bits of information. In practice, entanglement is fragile, which makes teleporting quantum information over any distance difficult. Graham and colleagues are instead relying on SuperDense Teleportation (SDT), which is a simplified and more efficient form of quantum communication. While SDT reduces the amount of information that can be teleported, the messages are more likely to get through than with normal teleportation. The researchers have successfully demonstrated their SDT system in the lab and are currently working to develop a version that could eventually be suitable for space-to-earth communication, e.g., from the ISS. Ultimately, the experiments could lead to a quantum network in space for secure communication, as well as potentially testing the effects of general and special relativity on quantum states.
BETTER INVISIBILITY CLOAKING
Friday, June 12, 12:06 PM, Room: Franklin CD
Late last year, Joseph S. Choi and John C. Howell (University of Rochester) demonstrated one of the first potentially practical invisibility cloak designs. Unlike many cloaks that require intricately structured materials (aka metamaterials), the cloak Choi and Howell built relied on conventional off-the-shelf lenses and optical components. Now, the researchers have proposed ways to improve the cloak further. Although the previously demonstrated design could hide objects from the naked eye, it would still be possible to tell that there was something strange going on by measuring characteristics of the light passing through the system. Light consists of waves, much like waves on water. While a cloak may not allow you to see what’s hiding behind it, the waves of light coming out it can be shifted farther forward or back relative to where you might expect them to be if there were no cloak or hidden object at all. All you need to do to tell that there’s a cloak (and potentially something hidden behind it) is to measure the so-called phase shifts in the out-of-step waves. But Choi and Howell have proposed a theoretical way to eliminate the shift, producing an essentially undetectable cloaking method, at least when viewed from a small range of directions.
Unfortunately, their work also supports the growing understanding that it’s not possible to cloak an object when viewed in full color from every direction.
PUBLIC LECTURE: Setting Traps for Antimatter - Dark Side of the Universe: beyond stars and the starstuff we are made of, Gerald Gabrielse (Harvard)
Tuesday, June 9, 8:00 PM, Hyatt Regency Ballroom
According to the best description of modern physics, the big bang created essentially equal amounts of antimatter and matter. As the universe cooled, the particles made of antimatter and matter should have annihilated each other as they collided. Trying to understand the great mystery of how and why a whole universe survived despite our “predictions” to the contrary has stimulated searches for tiny and unexpected differences between antimatter and matter. The containment of the charged and neutral antimatter to be studied is a significant challenge to this quest. This lecture describes antimatter containment in “traps” — containers with no walls — and illustrates the way that antimatter and matter are most precisely compared.
ATTENDEES’ MOST SCHEDULED TALKS
To see the most popular talks among physicists planning to attend the meeting go to: http://meetings.aps.org/Meeting/DAMOP15/TopEvent
OTHER TALKS OF INTEREST:
HUNTING FOR DARK MATTER WITH GPS AND ATOMIC CLOCKS
Tuesday, June 9, 3:18 PM, Room: Union ABC
QUANTUM TWIN PARADOX
Thursday, June 11, 9:12 AM, Room: Franklin CD
A theoretical look at the effects of General Relativity on quantum systems.
BEYOND MOORE’S LAW: TOWARDS COMPETITIVE QUANTUM DEVICES
Thursday, June 11, 9:12 AM, Room: Union ABC
ATOM INTERFEROMETRY ON A SOUNDING ROCKET
Friday, June 12, 10:30 AM, Room: Fairfield
HIGH-RESOLUTION IMAGING OF A SINGLE ATOM FOR DIRECT DETECTION OF ATOMIC MOTION
Friday, June 12, 8:00 AM, Room: Franklin CD
MOLECULAR STOPWATCHES, COGWHEELS AND SPINFLAKES
Thursday, June 11, 3:24 PM, Union DE
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