Lifeboat Foundation

Last year was awash with claims that researchers had found new high-temperature superconductors. While some of those claims were quickly quashed, others are still being explored, such as the report that single crystals of the nickelate La₃Ni₂O₇ can superconduct at up to 78 K when under a pressure of 18 gigapascals (GPa) [1]. Now experiments performed by Jinguang Cheng of the Chinese Academy of Science and colleagues strengthen the claim that this compound is indeed a superconductor [2]. If confirmed, these results would make La₃Ni₂O₇ one of the few transition-metal compounds outside of cuprates to superconduct at temperatures above the boiling point of liquid nitrogen.

The initial report of superconductivity in La₃Ni₂O₇ came from measurements of single crystals. Those experiments showed a sudden drop in electrical resistance at around 80 K in samples held at pressures above 14 GPa. However, the report lacked measurements of two key hallmarks of a material entering the superconducting state—its resistance falling to zero and the expulsion of external magnetic fields.

For their experiments, Cheng and his colleagues studied polycrystalline samples of La₃Ni₂O₇ subjected to pressures of up to 18 GPa. The researchers chose polycrystalline samples over single-crystal ones, as they are significantly easier to prepare. Their resistance measurements indicated the zero-resistance state needed to confirm the presence of superconductivity. But the researchers’ attempts to detect the magnetic hallmark of superconductivity failed. Cheng says that recent unpublished results from their lab show that doping La₃Ni₂O₇ with the lanthanide praseodymium increases the superconducting temperature to 82.5 K. In those experiments, he says, the team observed both superconducting hallmarks.

Muon spectroscopy serves as a crucial experimental method for exploring the magnetic characteristics of materials. This technique involves embedding a spin-polarized muon within the crystal lattice and observing the impact of the surrounding environment on its behavior. It operates on the principle that the muon will settle into a specific location predominantly influenced by electrostatic forces, a position that can be pinpointed through the calculation of the material’s electronic structure.

But a new study led by scientists in Italy, Switzerland, UK, and Germany has found that, at least for some materials, that is not the end of the story: the muon site can change due to a well-known but previously neglected effect, magnetostriction.

Pietro Bonfà from the University of Parma, lead author of the study just published in Physical Review Letters, explains that his group and their colleagues at the University of Oxford (UK) have been using density-functional theory (DFT) simulations for at least a decade to find muon sites.

Inspired by nature, nanotechnology researchers have identified ‘spontaneous curvature’ as the key factor determining how ultra-thin, artificial materials can transform into useful tubes, twists and helices.

Greater understanding of this process—which mimics how some seed pods open in nature—could unlock an array of new chiral materials that are 1,000 times thinner than a human hair, with the potential to improve the design of optical, electronic and mechanical devices.

Chiral shapes are structures that cannot be superimposed on their mirror image, much like how your left hand is a mirror image of your right hand but cannot fit perfectly on top of it.

Using cellulose from trees and a synthetic polymer, MIT researchers have created a material that “is stronger and tougher than some types of bone, and harder than typical aluminum alloys,” the university announced.

The researchers hope their compound could lead to better, more sustainable plastics in the future. Currently, the material shrinks while drying, making printing anything large out of it difficult.

“If you could avoid shrinkage, you could keep scaling up, maybe to the meter scale,” said MIT’s Abhinav Rao. “Then, if we were to dream big, we could replace a significant fraction of plastics with cellulose composites.”

There was a APS presentation by Ulsan Korea University researchers.

It is being reported that numerous comments on the Chinese website Zhihu imply that the University of Ulsan’s data plot is so important that a certain superconductivity expert saw the decisive signal proving LK99’s superconductivity in the graph’s temperature rise curve near 200K.

Nextbigfuture does not understand how a resistance rise implies any superconductivity but it is a thin film LK99-related material. Previously, LK99 thin film analysis by the original Korea researchers had found superconducting levels of resistance with chemically vapor deposited thin film.

Inspired by amphibians such as the wood frog, investigators designed and synthesized a new type of camouflage skin involving one-dimensional photonic crystal structures assembled in three-dimensional flexible gels.

As described in Advanced Optical Materials, the camouflage skin can quickly recognize and match the background by modulating the optical signals of external stimuli.

It demonstrated excellent mechanical performance, self-adaptive camouflage capabilities in response to complex surroundings, and long-term stability in real-world living environments. Bright structural color and mechanical flexibility were maintained even at temperatures as low as-80℃

Scientists at Rice University have uncovered a first-of-its-kind material: a 3D crystalline metal in which quantum correlations and the geometry of the crystal structure combine to frustrate the movement of electrons and lock them in place.

The find is detailed in a study published in Nature Physics. The paper also describes the theoretical design principle and experimental methodology that guided the research team to the material. One part copper, two parts vanadium, and four parts sulfur, the alloy features a 3D pyrochlore lattice consisting of corner-sharing tetrahedra.

Tellurite molybdenum quaternary oxides, a family of van der Waals materials, show slow group velocity and long lifetimes with promising implications for tunable low-loss anisotropic polaritonics.

Recent theoretical studies^36,37,38 have revealed that quasicrystalline superconductors exhibit several unconventional behaviors that are typically not observed in other known superconductors in periodic and disordered systems, thus opening a new field in the research of superconductivity. Nagai³⁶ has studied superconducting tight-binding models of Penrose and Ammann – Beenker lattices (typical two-dimensional quasicrystalline lattices) and demonstrated an intrinsic vortex pinning due to spatially inhomogeneous superconducting order parameter. Such an inhomogeneous order parameter arises from the quasicrystalline structural order, and therefore, the vortex pinning occurs without an impurity or defect. Sakai et al³⁷. have investigated quasicrystalline superconductivity using an attractive Hubbard model on a Penrose lattice using the real-space dynamical mean-field theory. Unconventional spatially-extended Cooper pairs were formed; the sum of the momenta of the Cooper pair electrons was nonzero, in contrast to the zero total momentum of the Cooper pair in the conventional BCS superconductivity. Such a nonzero total momentum of the Cooper pair is also observed for the Fulde – Ferrell – Larkin – Ovchinnikov (FFLO) state previously proposed for periodic systems^39,40,41,42. However, the unconventional Cooper pairing in the model QC is completely different from the FFLO state because the Cooper pairing occurs under no magnetic field. In addition, under a high magnetic field, a state similar to the FFLO state is formed in the model QC³⁸. However, this state is also different from the conventional FFLO state in periodic systems and forms a fractal-like spatial pattern of the oscillating superconducting order parameter, which is compatible with the self-similar structural order that is possessed by the QCs. As mentioned above, many interesting features are theoretically expected for superconducting QCs, which are yet to be demonstrated experimentally, and the Ta_1.6 Te dodecagonal QC phase in the present study offers a precious platform for it.

In conclusion, polygrain Ta_1.6 Te dodecagonal QC samples were fabricated by reaction sintering. Careful phase identification of the sample was performed by electron and powder X-ray diffraction experiments and diffraction-profile simulations. The samples were subjected to electrical resistivity, magnetic susceptibility, and specific heat measurements. The results unconditionally validate the occurrence of bulk superconductivity at a \({T}_{{{{{{\rm{c}}}}}}}\) of ~1 K. This is the first example of superconductivity in thermodynamically stable QCs. These findings are expected to motivate further investigations into the physical properties of vdW layered quasicrystals as well as two-dimensional quasicrystals. In particular, the dodecagonal QC provides a valuable platform for the experimental demonstration of the unique superconductivity theoretically predicted for QCs.