Manufacturing Bits: July 15

Atomtronics
The Institute of Electronic Structure and Laser of the Foundation for Research and Technology-Hellas (IESL-FORTH) and others have developed an atomtronic accelerator ring, a move that could advance the field of atomtronics.

Researchers have developed a small accelerator ring-shaped matterwave guide, which is capable of accelerating sub-atomic particles at hypersonic speeds. It could one day enable the development of sensitive quantum rotation and gravity sensors. The Cretan Matter Waves Group are also part of the research group.

Atomtronics, a sub-field of ultracold atomic physics, manipulates atoms to create devices using lasers. This is much the same way that electronics manipulates electrons to make devices.

Atomtronics promises to one day develop analogs of electronic circuits and devices using ultracold atoms. “These systems aim to realize semiconductor and especially diode and transistor behavior in atomic systems,” according to the Holland Group, a research group. “It is even possible to construct complete atomtronic circuits. Such circuits contain the analogue of electronic power supplies or batteries, and the necessary device connection analogs of electronic circuits and devices.”

The technology could also enable the development of small quantum devices and sensors, which could measure small forces or tiny rotations in systems, according to IESL-FORTH. For example, these devices could monitor water levels in deserts, according to the research group. In another example, these devices could be used in navigation when GPS fails.

To bring atomtronic devices a step closer, researchers from IESL-FORTH have demonstrated the coherent acceleration and transport of matterwaves in atomtronic waveguides. Researchers used a combination of magnetic fields at different frequencies. “The matterwaves reached hypersonic speeds exceeding Mach 16 (one mach = speed of sound) and guided the matterwaves for more than 40cm — an improvement of more than a factor of 1000 compared to the previous record,” according to IESL-FORTH.

Compact atomic gyroscopes
The National Institute of Standards and Technology (NIST) has upgraded its compact atomic gyroscope to enable new measurements.

NIST’s previous atomic gyroscope measured rotation. Now, the system has been upgraded to measure rotation, rotation angle and acceleration.

NIST’s atomic gyroscope.
Credit: J. Burrus/NIST

Gyroscopes are devices that help systems locate and know their orientation. NIST’s system could be used as a gyrocompass. A type of non-magnetic compass, a gyrocompass is used in ships and other systems. They use physics, gravity and the Earth’s rotation to find true north.

NIST’s gyroscope is based on an atom interferometer technology. Atom interferometry resembles today’s optical interferometry. Used in science and engineering, optical interferometers are specialized instruments. They measure displacements, refractive index changes, irregularities of surfaces and even gravitational waves.

Interferometers make measurements using two or more sources of electromagnetic waves. The waves are projected in a system and then superimposed. Then, the so-called interference pattern is measured and analyzed.

“Atom interferometry, however, hinges on quantum mechanics, the theory that describes how matter behaves at sub-microscopic scales,” according to NASA. “Atoms, which are highly sensitive to gravitational signals, can also be cajoled into behaving like light waves. Special pulsing lasers can split and manipulate atom waves to travel different paths. The two atom waves will interact with gravity in a way that affects the interference pattern produced once the two waves recombine.”

NIST’s gyroscope operates with the same principals, “taking advantage of the fact that atoms can act as both particles and waves,” according to NIST. “Rotation and acceleration are deduced from images of interfering matter waves (which show the probability of a particle’s position in space) from atoms in two different energy states.”

NIST’s system is a portable unit. Using point-source atom interferometry, the system makes use of a tiny cloud of atoms for the measurements. A glass chamber, which measures 1 cubic centimeter in volume, contains about 10 million cold rubidium atoms that are trapped and released.

“Not only did we build a simple quantum gyroscope, but this is the first time anyone has demonstrated simultaneous measurement of rotation, rotation angle and acceleration with a single source of atoms,” said Elizabeth Donley, a project leader at NIST. “Other gyroscopes, including the classical ones currently used in phones and planes, can measure only one axis of rotation. This is also the first time we’re reporting a sensitivity for the acceleration and rotation measurements.”