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Molecular clock transitions tune out the noise in the hunt for new physics

Heavy polar molecules are some of the most sensitive tools physicists have for probing what lies beyond the Standard Model, the theory that describes the particles and forces we know about. But turning that sensitivity into precise, trustworthy measurements has long been held back by one stubborn problem: Stray electric and magnetic fields drown out the tiny signals researchers are actually looking for.

In new research published in Physical Review X, a team led by Yuiki Takahashi at the California Institute of Technology has found a way around this, engineering molecular states that can consistently tune out this electromagnetic noise.

Detecting the body’s magnetic fields with a low-power Ramsey-based magnetometer

Our bodies generate extremely weak magnetic fields as electric currents flow through the heart, brain and other tissues. These signals are used in magnetocardiography and magnetoencephalography to assess heart function and brain activity, respectively. These fields can be detected at room temperature using diamond sensors containing nitrogen-vacancy (NV) centers, in which a carbon atom is replaced by a nitrogen atom adjacent to an empty lattice site.

However, conventional NV-center sensors typically require watt-level lasers to detect the extremely weak biomagnetic fields, which are usually below the picotesla level. These high-power lasers generate significant heat, limiting how close the sensor can be placed to biological tissue. Since biomagnetic fields rapidly weaken with distance, overcoming thermal and close-proximity challenges is essential for practical biomagnetic sensing.

A research team led by Professor Takayuki Iwasaki from the Department of Electrical and Electronic Engineering, School of Engineering, Institute of Science Tokyo, Japan, has developed a diamond quantum magnetometer using a low-power laser of just 210 mW, a light-trapping diamond waveguide and a compact microwave antenna. The new sensor limits its temperature rise to only 13 K while allowing it to be placed just 2 mm (0.08 inches) from the sample, enabling close-proximity biomagnetic measurements without compromising thermal safety.

From quantum error correction to emergent gravity: Probing holographic universes at QLab

One of the deepest ambitions in modern physics is understanding how the fabric of space and time could emerge from fundamental quantum degrees of freedom to establish a quantum theory of gravity.

In the new paper, “Observation of gravity-like signatures in holographic codes on a quantum computer,” posted to the arXiv preprint server, researchers from the National Quantum Laboratory (QLab@UMD), the Duke Quantum Center, the Virginia Tech Center for Quantum Information Science and Engineering, Caltech’s Institute for Quantum Information and Matter, IonQ and BlueQubit have successfully simulated toy models of quantum gravity according to the AdS/CFT correspondence. The team, led by Crystal Noel and Charles Cao, includes quantum-computation pioneers John Preskill and Christopher Monroe.

Using the IonQ Forte ion-trap quantum computer, the study implements the intriguing HaPPY quantum error-correction code, which forms a bridge between quantum computing and quantum gravity. This code simulates a highly simplified model of a universe with a negative cosmological constant that features a so-called bulk-boundary correspondence, in which the properties of a higher-dimensional gravitational universe (bulk) are completely determined by a lower-dimensional quantum system without gravity living on the boundary. The team successfully demonstrated fundamental entanglement properties of these systems.

Scientists Find a More Precise Way to Grow Artificial Blood Vessels, Using Magnets

Science may one day give us a way to replace damaged and diseased parts of the body with artificial replacements – but reproducing organs and tissues in the lab isn’t easy.

That’s especially true for networks of blood vessels, which at the level of fine, thread-like capillaries are microscopic – these capillaries can be as small as 0.005 millimeters (34 times thinner than a human hair), and only let blood cells through in single file.

Researchers led by a team from MIT have now published a study in PNAS that details a way of engineering blood vessels in the lab with significantly greater precision than before.

New mechanism explains how spinal stimulation improves arm movement after stroke

Researchers in the Neuromechatronics Lab at Carnegie Mellon University have already proven that spinal cord stimulation can help people regain movement after stroke, but until now they didn’t quite know how.

In a new study, published today in Cell Reports Medicine, a research team led by Doug Weber, professor of mechanical engineering and neuroscience, and Ph.D. candidate Luigi Borda report that epidural spinal cord stimulation works by restoring inhibitory spinal circuits. These circuits enable the nervous system to coordinate opposing muscles, such as the biceps and triceps, which must work together to bend and straighten the elbow. After a stroke, those neural control circuits are disrupted. The new study found that spinal cord stimulation helps restore that balance, allowing stroke survivors to move their arms more smoothly, quickly and efficiently.

“This discovery allows us to move beyond simply strengthening weak muscles; we can now fine-tune stimulation to release the ‘brakes’ on overactive muscles, providing a more effective and personalized path to recovery,” said Weber.

Before babies can hear, their brains are already wiring for sound

Long before a baby’s ears are functional, the brain is already building the circuitry needed for hearing, according to new research from Johns Hopkins University. Published in the journal Science Advances, the study in mice identifies a previously unknown neural “shortcut” that organizes the auditory system before birth, offering new insight into how the auditory system prepares to process sound and eventually learn language.

While it’s well-known that sound travels from the ear to the auditory cortex, the brain’s hub for hearing, Johns Hopkins researchers discovered a new neural circuit that bypasses the ear entirely. Their findings show that the frontal cortex—the region involved in vocalization—sends signals directly to the auditory cortex, allowing the developing brain to activate hearing-related circuits before external sounds can be heard.

“Our results provide the first direct functional evidence of this biological shortcut that doesn’t go through hearing,” says senior author Patrick Kanold, a professor of biomedical engineering and neuroscience at Johns Hopkins. “It’s a novel brain activity source that can shape the earliest development in mammals, like interpreting information and discerning complex sounds.”

Braided, exotic particles could build reliable, universal quantum computers

A truly useful quantum computer must be able to run any algorithm, with the same versatility an ordinary laptop offers. Physicists have now shown a new way to give a quantum computer exactly that flexibility, harnessing the capabilities of exotic quantum particles called non-Abelian anyons.

A team of scientists from the University of Chicago Pritzker School of Molecular Engineering (UChicago PME), Harvard, Stony Brook University and Quantinuum built and tested a complete toolkit of operations using non-Abelian anyons, proving for the first time the broad utility of this approach.

“We demonstrated a so-called universal gate set—meaning that if you store information in these emergent versions of quarks, and you move them around, you can do any quantum computation you might want to do,” said Ruben Verresen, assistant professor of molecular engineering at UChicago PME and a co-author of the new study published in Nature.

Physicists create first room-temperature quantum material

Quantum materials could transform technologies ranging from powerful computers and ultrasecure communications to advanced energy systems. But there has always been one major obstacle.

Nearly all known quantum materials exhibit their remarkable properties only when cooled to temperatures close to absolute zero. At room temperature, heat creates constant atomic vibrations that overwhelm the delicate quantum behavior scientists are trying to harness. Keeping those vibrations in check requires bulky cryogenic refrigeration systems, making quantum materials powerful tools in the laboratory but difficult to translate into practical technologies.

In a study published in Nature, LSU physicists have developed the first room-temperature quantum material capable of distinguishing and transporting different quantum states of light, overcoming one of the biggest challenges in quantum materials research. Led by Associate Professor of Physics Omar S. Magaña-Loaiza, the work establishes a general design principle for engineering an entirely new class of quantum materials, opening new possibilities for quantum computing, secure communications, sensing technologies and advanced energy systems.

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