Within tiny halos of light clinging to a vanishingly thin wisp of optical fiber, scientist Jongmin Lee guides atoms like marbles through a narrow pipe. Rock the fiber and the atoms shift side by side; they just don’t fall off. But don’t be deceived by the seemingly delicate nature of his experiment. Lee is exploring how to measure motion precisely in rough-and-tumble environments.

A quantum sensing scientist at Sandia National Laboratories, Lee is an expert in a type of motion sensor called an atom interferometer. In a lab, this device uses quantum mechanics to obtain exquisitely accurate measurements. Lee and his team are working toward building an extremely small, low-power version for field use—small enough to fit on a specialized type of microchip called a photonic integrated circuit.

Their latest results were published in the journal AVS Quantum Science, where the team reported trapping cesium atoms on a fiber only 420 nanometers in diameter with just 5 milliwatts of optical power—about 2,000 times less power than an LED bulb uses. With just 150 nanowatts, the researchers can also take measurements that mimic atom interferometry.

A Stanford team has documented the first direct observation of quantum jumps of sound in a mechanical resonator, completing an arc of scientific exploration that started more than 100 years ago.

Quantum jumps—sudden transitions from one energy state to another—have been theorized since the early 1900s. Scientists first demonstrated these jumps in trapped ions in 1986 and later in photons, the fundamental particles of light, in 2007. Observing quantum jumps of sound had remained elusive, but a team led by Stanford physicist Amir Safavi-Naeini has recorded these phenomena, publishing the findings in the journal Science.

“What this study shows will allow us to move forward with developing new quantum technologies with sound,” said Safavi-Naeini, associate professor of applied physics in the Stanford School of Humanities and Sciences. “We have seen that vibrating objects can exhibit quantum behavior, which is the prerequisite for many of the operations needed by quantum computing and sensing.”