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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.

Frozen fiber couples light and sound 1,000 times more strongly than standard glass fibers

Researchers have developed a new type of optical fiber by freezing a glass capillary filled with liquid. It guides light and sound waves simultaneously and enables highly efficient coupling between them. The high coupling strength lowers the energy consumption of photonic neuromorphic computing schemes and quantum signal processing applications by several orders of magnitude.

When volcanoes erupt, one can observe streams of liquid lava cool and solidify into rock formations at the bottoms of volcanoes. The same physical process—a liquid changing into a solid phase upon cooling—can be observed when lakes start freezing during cold winters. These phase changes always come with changes in the physical properties of the material, such as the density or refractive index that govern how sound and light move through it.

This fundamental physical process is also used during the melting of glass preforms to loosen their structure while drawing optical fiber. These fibers then guide light through their cores, allowing the transmission of information via light very quickly over long distances, which is why they are widely used for telecommunications applications.

A New Compact Instrument Enables High-Fidelity Measurements of Energetic Particles on CubeSats

Successfully launched on July 23, 2025, the REAL instrument can distinguish between these potential modes, making it possible to investigate their relative importance and determine which, if any, waves are responsible for electron fallout. Leveraging recent advancements in sensor miniaturization, the instrument includes three sensor heads — a low-, medium-, and high-energy head with two, five, and four simultaneous look directions, respectively — integrated with four electronic boards. Together, they occupy only about half of the REAL CubeSat and use a time resolution sufficient to resolve microbursts of electrons with energies ranging from 40 keV up to 2 MeV. As its parent 3U CubeSat flies in LEO, REAL points along Earth’s magnetic field and can simultaneously measure the quantity, energy, and angle of the particles as they fall into the atmosphere — a first-of-its-kind capability.

“Most CubeSats can observe particles from only a single direction, so they have to spin in order to build up a full picture — and that takes a few seconds, too slow to capture microbursts,” said space physicist Robyn Millan of Dartmouth College, who serves as the REAL mission principal investigator. “With REAL, we’ve managed to squeeze three sensors, each with multiple look directions, into the top of this 100-by-100-millimeter head, allowing us to capture those measurements all at once. We’re really proud of that.”

The high-energy head consists of a 30-millimeter-thick aluminum collimator with four apertures, each spanning 20 degrees of pitch angle. Each aperture connects to an active area on a solid-state detector (SSD) at the base. The medium-energy head similarly uses an SSD base but instead employs five active areas that connect to a 22-millimeter-thick aluminum collimator with five apertures, each spanning 20 degrees of pitch angle. The low-energy head, on the other hand, is a miniature electrostatic analyzer (ESA) consisting of titanium electrodes sandwiched between etched silicon selector slits. These lie on top of a microchannel plate (MCP). The low-energy head uses 36 apertures, two look directions (±40 degrees), and 15 channels to measure electrons with lower energies, from 1 keV to 40 keV.

How quantum circuits based on neutral atoms could find and fix errors

Quantum computers, devices that process information by leveraging the laws of quantum mechanics, have been found to outperform classical computers in some advanced tasks. Instead of storing information in the form of classical binary bits (i.e., 0 or 1), quantum computers rely on quantum bits (i.e., qubits), which can also exist in combinations of 0 and 1 states.

Despite their potential, quantum computers are known to be highly prone to errors. This is because qubits are very sensitive to heat, magnetic fields and other changes in their surroundings, which can disrupt the delicate quantum states they rely on to store and process data.

Researchers at Princeton University recently introduced a new approach for developing quantum computers that make fewer errors and whose errors are easier to detect and correct.

A scheme to verify gates of a quantum computer without examining devices

Quantum computers, systems that process information using the principles of quantum mechanics, could solve some problems that cannot be tackled by the classical computers currently used worldwide. Despite their potential, verifying that these computers are working correctly and can reliably perform computations remains challenging.

Shubhayan Sarkar, a researcher at the University of Gdansk, recently introduced a new scheme for certifying that quantum chips (unitary gates) in a quantum computer are operating correctly without relying on assumptions about their internal components. This scheme, introduced in a paper published in Physical Review Letters, uses an approach referred to as almost device-independent (DI) certification.

“Consider the computer you are using right now,” Sarkar told Phys.org. “If it provides the answer to a mathematical problem, how do you know that the computation is correct? In practice, we rarely verify every calculation ourselves.

New topology-based biomarkers may improve breast cancer prediction

For decades, pathologists have diagnosed and graded breast cancer by looking at tissue samples under a microscope, searching for telltale signs of disorder in the structure of cells and tissues. Now, researchers at Columbia and their collaborators have developed a new computational approach that transforms those visual patterns into quantitative measurements, potentially improving how clinicians predict breast cancer outcomes and choose therapies.

In a recent study published in Cancer Research, researchers used mathematical tools known as topology to develop biomarkers quantifying the organizational structure of breast cancer tissue. The approach generated continuous numerical scores that predicted patient survival and treatment response more accurately than many traditional biomarkers, while also showing less variation across racial and ethnic groups.

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