Manufacturing Bits: Sept. 15

Lasersabers and laser swords
In 2013, the California Institute of Technology, Harvard and the Massachusetts Institute of Technology (MIT) found a way to bind two photons, thereby forming photonic molecules.

To accomplish this feat, Caltech, Harvard and MIT pumped rubidium atoms into a vacuum chamber. They used lasers to cool the atoms. Then, they fired photons into a cloud of atoms. This, in turn, caused the atoms to slow.

This breakthrough prompted some to believe that the technology could one day be used to develop lightsabers, or laser swords, as the ones that are used in the science fiction movie classic Star Wars.

Now, the National Institute of Standards and Technology (NIST), the University of Maryland and others have built upon this research. Researchers from NIST and others have tweaked the photon binding process. In doing so, they found the photons could travel side by side and at a specific distance from each other.

Researchers show that two photons can be locked together at a short distance. (Credit: E. Edwards/JQI)

Researchers provided few details about the breakthrough. “It’s not a molecule per se, but you can imagine it as having a similar kind of structure,” said NIST’s Alexey Gorshkov, on the agency’s Web site. “We’re learning how to build complex states of light that, in turn, can be built into more complex objects. This is the first time anyone has shown how to bind two photons a finite distance apart.”

Gorshkov does not foresee the advent of saberlasers anytime soon, but the technology could be applied elsewhere. “Lots of modern technologies are based on light, from communication technology to high-definition imaging,” Gorshkov said. “Many of them would be greatly improved if we could engineer interactions between photons.”

Spintronics in action
Using scanning transmission X-ray microscope, the Department of Energy’s SLAC National Accelerator Laboratory has imaged spin currents as they travels across materials. The result is a step toward realizing post-CMOS devices based on spintronics.

One type of spintronic-based device is MRAM. MRAM uses the magnetism of electron spin to provide non-volatility. It delivers the speed of SRAM and the non-volatility of flash with unlimited endurance. In addition, spin-based logic is also attractive because it combines the switching speeds of logic and the non-volatility of memory.

In the lab, meanwhile, researchers from SLAC and others created a spintronics test device. The spin current flowed from a cobalt-based magnetic material. Then, to look at the spin, researchers customized a specialized X-ray microscope and detector system at the Stanford Synchrotron Radiation Lightsource (SSRL). SSRL produces bright X-rays as a resource for researchers to study the world at the atomic and molecular level.

A scanning transmission X-ray microscope at SSRL. (Source: SLAC)

With the technology, researchers could pick up the magnetic signal generated by as few as 50 atoms. They also made another discovery: The current loses more than half of its magnetic spin strength. “We see that most of the magnetization gets lost here at the interface between the two materials,” said researcher Roopali Kukreja on SLAC’s Web site. “This was an ‘Oh, wow!’ moment because nobody had suspected this. The copper atoms at the interface are almost magnetic, and that is where you really lose the spin property of this current. The role of this interface was not clear before.”

World’s largest camera
The Department of Energy has approved the start of construction of the world’s largest digital camera. The 3.2-gigapixel digital camera will be used for the Large Synoptic Survey Telescope (LSST).

The LSST is an 8.4-meter ground-based telescope. Starting in 2022, LSST will detect tens of billions of objects. It will take digital images of the entire visible southern sky from atop a mountain called Cerro Pachón in Chile. Assembled at the DOE’s SLAC National Accelerator Laboratory, the camera will be the eye of LSST. The camera is the size of a small car and weighs more than three tons. It will capture images equivalent to 1,500 high-definition television screens.

The LSST’s camera will include a filter-changing mechanism and shutter. (Source: SLAC)