暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
暂无摘要（点击查看详情）
A Python program for calculating the metrics necessary to perform information-theory based symmetry classifications and quantifications of transmission electron diffraction spot patterns is introduced. It is the first of its kind, in that it implements objectivity into crystallographic symmetry classifications and quantifications of approximate zone axis patterns from crystals. The equations by which the program operates as well as the required inputs are given. The results of the program's analysis of an experimental transmission electron diffraction spot pattern from a crystal with a pseudo-hexagonal lattice metric and a rectangular-centered Bravias lattice is used as an example. The program will eventually be appended to allow analysis of the other hierarchical translational pseudo-symmetry and Bravais lattice type combinations. Crystallographic Rsym values of traditional classifications into projected point symmetry groups are provided alongside information-theoretic results of the new program's analysis for comparison purposes.
We consider a bosonic $s$ and $p$ orbital system in a face-centered cubic (FCC) optical lattice, and predict a fluctuation-induced instability towards the orbital analogue of Palmer-Chalker state, which is originally proposed in an electronic spin system. For bosons loaded in the FCC optical lattice, the single-particle spectrum has four degenerate band minima with their crystal momenta forming a tetrahedron in Brillouin zone. In the weakly interacting regime, the ensuing many-particle ground state, at the classical level, underlies a four-sublattice tetrahedral supercell of spontaneously generated $p$-orbital angular momenta through the Bravias-Bloch duality between real and momentum space, and is macroscopically degenerate originating from the geometric frustration. The fluctuations on top of the classical ground state lift its degeneracy and select the Palmer-Chalker ordering of $p$-orbital angular momenta as the quantum ground state through order-by-disorder mechanism. These findings raise the exciting possibility of simulating the Palmer-Chalker state with its orbital counterpart in ultracold atomic gases.
Artemis II proved NASA’s deep space systems are ready for the next leap。 Orion survived its high-speed return with improved heat shield performance and pinpoint landing accuracy, while the SLS rocket nailed its trajectory。 Even the launch pad upgrades paid off, with minimal damage despite the powerful liftoff
Physicists may have just cracked open a hidden side of the quantum world。 For decades, every known particle was thought to belong to one of two categories — bosons or fermions — but researchers have now shown that bizarre “in-between” particles called anyons could also exist in a one-dimensional system。 Even more exciting, these strange particles m
Scientists are using sunlight to turn plastic waste into clean fuels like hydrogen, offering a breakthrough solution to both pollution and energy challenges。 While still in development, the approach could transform trash into a valuable resource for a low-carbon future
A bizarre planetary pairing 190 light-years away is challenging everything astronomers thought they knew about how worlds form。 A “lonely” hot Jupiter — typically found without nearby companions — is sharing its system with a smaller mini-Neptune tucked even closer to the star, a setup once thought nearly impossible