Scientists come a step closer in controlling how matter behaves

Washington, March 25 (ANI): A team of scientists has used laser light to control x-ray beams, which is a step toward controlling how matter behaves, shaping x-rays with other x-rays, and eventually directing the paths chemical reactions can take.

Working at the Berkeley Lab's Advanced Light Source's femtosecond beamline 6.0.2, the team of scientists shows how it can be done.

As a new generation of powerful light sources comes online, intense x-ray beams may be able to control matter directly and allow one beam of x-rays to control another.

Using the ALS's femtosecond (quadrillionth of a second) spectroscopy beamline 6.0.2, Thornton E. Glover and his colleagues sent ultrashort pulses of laser light and higher-frequency x-rays together through a gas cell filled with pressurized neon.

Excited by the laser pulses, the gas, which normally absorbs x-rays, became transparent to the x-ray pulses during their quick passage.

"We were inspired by the interesting new science demonstrated in quantum optics experiments that use visible light to control visible light," said Glover.

"One spectacular example is slowing light to a near standstill in some media. The ability to, in effect, stop light in a medium has potential applications for quantum information storage and processing," he added.

Glover said that another example of optical control is using visible light to induce transparency in a medium.

"We embarked on our own research in the hope that it would lead to new and interesting ways to use x-rays as well as visible light," he said.

The experiment's intense laser pulses created brief coherent superposition states in the dense neon gas inside the cell, which rendered the pressurized neon in the gas cell transparent to the x-rays.

"Quantum mechanicaly speaking, there is destructive interference between two absorption pathways and this reduces the absorption," said Glover. "That is, it makes the medium transparent," he added.

For the first time, optical pulses had been used to control how x-rays interact with matter.

The experimenters quickly put this ephemeral neon window to practical service, using it to measure the duration of the femtosecond-scale x-ray pulse to high accuracy more simply than has been possible before, with the added ability of shaping x-ray pulses on a femtosecond time scale.

"By demonstrating a way to shape x-rays on the femtosecond time scale, we've opened the door to 'quantum control' experiments - now possible only with long-wavelength light - in the x-ray egime," said Glover. (ANI)