<html><head></head><body>Controlled defects in the dense lattice of a&nbsp;diamond’s carbon matrix create one of the&nbsp;few systems available for exploring quantum&nbsp;phenomena at room temperature, instead of&nbsp;the supercooled environment typically required.&nbsp;The problem is creating precise defects in&nbsp;diamond’s adamantine structure.Nathalie de Leon, an associate professor of&nbsp;electrical and computer engineering, has pioneered the production of diamonds with calibrated defects. Diamond is made up of tightly&nbsp;packed carbon atoms, and de Leon’s team&nbsp;specializes in replacing two carbon atoms with&nbsp;one of nitrogen and a carefully placed empty&nbsp;space, or vacancy, in the atomic lattice.These introduced defects, called nitrogen-vacancy (NV) centers, have useful quantum&nbsp;properties. The vacancy can trap electrons that&nbsp;spin in a controlled manner. The way the electrons spin — a promising feature for encoding quantum information — is exquisitely sensitive&nbsp;to pulses of laser light, microwave radiation, or&nbsp;magnetic fields.The NV centers’ sensitivity also opens a path&nbsp;toward imaging the structures of single molecules. By measuring the tiny magnetic fields&nbsp;arising from electrons and nuclei, scientists&nbsp;could use the NV centers to study the structures of molecules like proteins, which are&nbsp;critical to cellular functions.To get a picture of the molecule, it needs to&nbsp;hold still, and binding molecules to diamond is&nbsp;incredibly difficult. In fact, it had eluded efforts&nbsp;for decades until de Leon, Princeton chemistry&nbsp;professor Robert Knowles, and their collaborators uncovered a chemical technique for&nbsp;attaching target molecules. Now, Lila Rodgers,&nbsp;a Ph.D. student who was part of the research team, is working to improve the method. Besides uncovering new chemistry to bond different kinds of molecules, Rodgers is working to eliminate microscopic nicks or rough spots caused by the process that could interfere with a sensor. This type of single-molecule sensing could improve the ability to study the dynamic structures of proteins as they change in response to their environment — a potential boon to biology and pharmaceutical research, said Rodgers.</body></html>

Nathalie de Leon. Photo by Sameer A. Khan/Fotobuddy

A perfect diamond may be a jeweler’s dream, but for quantum scientists, beauty lies in a stone’s tiny defects. These flaws hold the power to trap and control single electrons, opening possibilities for both quantum computing and mapping molecular structures.

Defects in diamond could sense structures of single molecules

materials

Using specially designed diamonds with nitrogen-vacancy centers, researchers at Princeton University and the University of Wisconsin-Madison have developed a technique to measure noise in a material by studying correlations, and they can use this information to learn the spatial structure and time-varying nature of the noise. In this image, a diamond with near-surface nitrogen-vacancy centers is illuminated by green laser light from a microscope objective lens. Photo by David Kelly Crow

Electromagnetic noise poses a major problem for communications, prompting wireless carriers to invest heavily in technologies to overcome it. But for a team of scientists exploring the atomic realm, measuring tiny fluctuations in noise could hold the key to discovery.

New technique reveals changing shapes of magnetic noise in space and time

Princeton researchers have found that human-language descriptions of tools can accelerate the learning of a simulated robotic arm lifting and using a variety of tools. Animation by the researchers; GIF by Neil Adelantar

Exploring a new way to teach robots, Princeton researchers have found that human-language descriptions of tools can accelerate the learning of a simulated robotic arm lifting and using a variety of tools.

Words prove their worth as teaching tools for robots

Researchers at Princeton University and the University of Washington have developed an ultracompact camera the size of a coarse grain of salt. The system relies on a technology called a metasurface, which is studded with 1.6 million cylindrical posts and can be produced much like a computer chip. Image courtesy of the researchers

Micro-sized cameras have great potential to spot problems in the human body and enable sensing for super-small robots, but past approaches captured fuzzy, distorted images with limited fields of view.

Researchers shrink camera to the size of a salt grain

If you’ve been listening to more podcasts while stuck at home this year, you may have noticed a side effect of the uptick in virtual conversations: a decline in audio quality. Interviews conducted by phone or video chat often include background noise, reverberation and distortion.

More by Molly Sharlach

New technique reveals changing shapes of magnetic noise in space and time

Words prove their worth as teaching tools for robots

Researchers shrink camera to the size of a salt grain