The NVision Quantum Technologies team manipulated and read out the spin state of a single carbene molecule with a laser at 4.5 Kelvin, retaining its spin quantum properties for about 2.2 milliseconds. The single molecule's emission frequency remained stable for more than an hour. The work was published in Nature under the title A single-molecule spin–photon interface, DOI 10.1038/s41586-026-11147-6.
Why we recommend it: The study reports measurements of both single-molecule spin retention time and emission-frequency stability, offering concrete experimental evidence for assessing molecules as potential quantum network nodes.
Researchers at Yokohama National University developed an exactly solvable model of a cavity-coupled one-dimensional Ising spin chain. They found that cavity photons can mediate long-range interactions, inducing a second-order magnetic phase transition and a macroscopic optical field at finite temperatures. In the thermodynamic limit, the team analytically derived the magnetization, photon number, and critical temperature. The work was published in Physical Review Research; future work is expected to incorporate energy loss.
Why we recommend it: The exactly solvable model provides magnetization, photon-number, and critical-temperature results, offering a reference for analyzing how light-matter coupling changes phase transitions in one-dimensional systems at finite temperatures.
A University of Pennsylvania team transferred single-photon skyrmion topology on a chip to a shared two-photon quantum state, and found that the topological properties persisted after entanglement vanished. The team gradually introduced interference, including background light, and found that the topology was disrupted only under stronger interference. Quantum correlations measured by quantum discord remained after entanglement vanished. The findings, published in Nature Physics, offer clues for exploring how robust topological patterns could protect quantum information.
Why we recommend it: In a chip experiment, topology persisted after photon entanglement vanished, providing new experimental clues about the relationship between topology and broader forms of quantum correlation.
An international research team combined NV-doped diamond with a semiconductor laser to achieve 100% measurement contrast for all three components of a magnetic field. Near the laser threshold, small losses from NV center absorption can suppress laser output. Based on tests, the team calculated a best possible sensitivity of 127 fT/ÖHz in one direction and below 400 fT/ÖHz for all three vector components, with optimal sensitivity achieved at the cost of a limited dynamic range. The study was published in Nature Communications, with DOI 10.1038/s41467-026-78386-z.
Why we recommend it: The research boosts magnetic field measurement contrast through loss amplification near the laser threshold, providing a concrete case for understanding the trade-off between sensitivity and dynamic range in diamond magnetic sensing.
A theoretical physics team at Emory University proposed using light to detect the spectral fingerprints of anyons and thereby localize them in materials. Models and simulations predict that excitons in atomically thin semiconductors can bind with nearby anyons to form exciton-anyon states, producing detectable energy shifts. The study was published in Physical Review Letters, and the team hopes experimental work will further test this theoretical scheme.
Why we recommend it: The study translates the coupling of excitons and anyons into detectable spectral energy shifts, offering a concrete theoretical pathway for using light to localize collective electronic excitations.
The University of Science and Technology of China and other institutions have developed a thin-film lithium niobate quantum frequency converter that can convert 393 nm ultraviolet light into light in the 1550 nm telecom band. The device uses a periodically poled optical waveguide, and tests achieved an external photon conversion efficiency of 28.8% and a background noise rate of 35 counts per second. The team also connected the optimized conversion module to a 40Ca+ trapped-ion system, laying the groundwork for fiber interconnection of quantum nodes that emit ultraviolet light.
Why we recommend it: The study controls noise by exploiting the different tuning behaviors of difference-frequency generation and pump-induced nonlinear noise, offering a method that can be applied to other quantum frequency conversion processes.
AIST researchers directly observed flux quanta generated when a superconductor absorbs photons and demonstrated a detection principle that identifies photon numbers based on their count. The method reads quantized voltage signals produced by the Josephson effect as flux quanta cross the superconductor, without waiting for a thermal response, promising high-speed photon counting. The results were published in Physical Review Applied, DOI 10.1103/n295-rfl8.
Why we recommend it: The study shifts photon counting readout from thermal response to superconducting phase dynamics, offering a new comparative perspective on the trade-off between photon number resolution and detection speed.
Researchers at Fraunhofer IAF have demonstrated a diamond NV-center laser-threshold magnetometer achieving 100% optical contrast and coherent laser readout of up to 50 mW. Under photon-shot-noise-limited conditions, the sensitivity of each of the three components of the magnetic-field vector can be below 400 fT/√Hz. Compared with conventional NV fluorescence sensors and vapor-cell magnetometers, the system improves the ratio of the sensitivity limit to dynamic range by up to 590 times while retaining vector measurement capability.
Why we recommend it: Using diamond NV centers as a magnetic-field-dependent loss channel inside a laser cavity offers a concrete experimental route for understanding the trade-off between high sensitivity and large dynamic range.
A joint team from the Institute of Physics in Zagreb and PMF has experimentally observed one-dimensional discrete solitons for the first time in an optically induced photonic lattice in warm rubidium vapor. At a probe laser power of about 6 mW, nonlinear self-focusing counteracts discrete diffraction, and the beam maintains an almost invariant transverse profile as it propagates. The study was published in Laser & Photonics Reviews; a model incorporating the full atomic hyperfine structure agrees with the experiment, and the lattice can be tuned via the coupling beam frequency and intensity.
Why we recommend it: By comparing a laser-written tunable lattice with an atomic response model, this experiment provides a concrete case for understanding how discrete diffraction and nonlinear self-focusing balance each other.
Researchers at the University of Oxford have kept remote memory qubits entangled for about 10 seconds in a two-node ion quantum network connected by optical fiber. Each node contains one strontium ion and one calcium ion. Photons emitted by the strontium ions establish remote entanglement through Bell-state measurement, and local operations then extend the entanglement to the calcium ions, creating three- or four-ion entangled states across the nodes.
Why we recommend it: Strium ions handle the long-distance link, while calcium ion storage extends the entanglement lifetime from the millisecond scale of network qubits to more than 10 seconds.
An international research team used extreme ultraviolet (XUV) pulses to control the interference of two stimulated Raman pathways by adjusting the optical field phase, altering the excitation yield of the helium He(2s) bound state. The experiment was carried out at the FERMI free-electron laser facility in Italy, and the results were published in Nature Photonics. The team believes the concept could eventually be used in element-specific imaging and spectroscopy tools to track electron motion and chemical transformations.
Why we recommend it: Varying the phase of the extreme ultraviolet field changes the interference of two stimulated Raman pathways, showing a route for extending coherent control methods from visible and infrared light to higher-energy spectral regions.
A research team at KTH Royal Institute of Technology has demonstrated a programmable photonic chip that can emulate dissipative systems and detect and measure their topological properties. The work uses a mathematical method to simulate loss without actually losing the signal, then compares the light with a reference beam to distinguish topological scenarios from ordinary ones and detect exceptional points. The results were published in Physical Review Letters, and the same chip can be reprogrammed to test different scenarios.
Why we recommend it: The study reads out topological information in dissipative systems through reference-beam interference and tests different scenarios on the same programmable chip, providing a method for investigating robust properties under loss conditions.
Researchers have developed and demonstrated a GaP-on-diamond hybrid nanophotonic platform enabling controlled interaction between photons and silicon-vacancy (SiV) centers in diamond. Using stamp transfer, the team fabricated more than 600 nanophotonic cavities on a diamond substrate with a yield of 99.5%, achieving cooperativity above 1 and a spin relaxation time exceeding 0.4 milliseconds, enabling single-shot readout of SiV electron spins. Next steps include connecting multiple devices on the same chip and demonstrating entanglement.
Why we recommend it: A transfer process that avoids etching the diamond balances device yield with spin-photon coupling, offering a concrete example of how quantum network interfaces could move toward scalable manufacturing.
Researchers integrated gallium phosphide (GaP) nanophotonic cavities onto a diamond substrate using a stamp transfer process, enhancing quantum optical interaction with diamond color centers. The devices are first fabricated by electron-beam lithography in a GaP thin film on a carrier, screened by spectroscopic testing, and then transferred. Experiments achieved cooperativity above 1. The platform can serve as a light-matter interface in quantum networks.
Why we recommend it: The source details the heterogeneous integration process and the screening-and-transfer workflow, offering useful reference for fabrication routes for diamond color center quantum photonic devices.
A paper in Science reports that researchers entangled a levitated glass nanosphere with an optical field in an optical trap, achieving the effect at room temperature and providing a new platform for macroscopic quantum mechanics research.
Why we recommend it: The original article reports entanglement of a macroscopic object with light at room temperature, relevant to optomechanics and quantum sensing
Why we recommend it: The original paper transmitted a high-dimensional cluster state over actually deployed fiber, offering useful lessons for quantum network engineering
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Shanghai Institute of Optics and Fine Mechanics (SIOM) · Research UpdatesOptics industryPicksAI score6363
Researcher Tian Ye and Academician Li Ruxin at the Shanghai Institute of Optics and Fine Mechanics (SIOM), together with Researcher Pan Yiming at ShanghaiTech University and colleagues, have proposed a new mechanism that uses the quadratic phase accumulated during the propagation of free-electron quantum wave packets to simultaneously achieve selectable high-harmonic bunching and synthesis of nonclassical quantum light, linking quantum state control, high-harmonic radiation and quantum light synthesis.
Why we recommend it: The original paper proposes a unified framework for free-electron lasers and quantum light sources, relevant to novel light source research
Shuo Sun and colleagues used fishbone photonic crystal cavities to combine diamond nanobeams with titanium dioxide integrated optical circuits, achieving heterogeneous integration.
Why we recommend it: The original paper presents a new structure coupling diamond color centers to integrated optical circuits, relevant to quantum photonic chips
Researchers at TU Wien propose that letting photons change shape as they propagate could enable perfect quantum information transfer between quantum network nodes.