1,848 research outputs found
Quantum Interactions in Topological R166 Kagome Magnet
Kagome magnet has been found to be a fertile ground for the search of exotic
quantum states in condensed matter. Arising from the unusual geometry, the
quantum interactions in the kagome lattice give rise to various quantum states,
including the Chern-gapped Dirac fermion, Weyl fermion, flat band and van Hove
singularity. Here we review recent advances in the study of the R166 kagome
magnet (RT6E6, R = rare earths; T = transition metals; and E = Sn, Ge, etc.)
whose crystal structure highlights the transition-metal-based kagome lattice
and rare-earth sublattice. Compared with other kagome magnets, the R166 family
owns the particularly strong interplays between the d electrons on the kagome
site and the localized f electrons on the rare-earth site. In the form of
spin-orbital coupling, exchange interaction and many-body effect, the quantum
interactions play an essential role in the Berry curvature field in both the
reciprocal and real spaces of R166 family. We discuss the spectroscopic and
transport visualization of the topological electrons hosted in the Mn kagome
layer of RMn6Sn6 and the various topological effects due to the quantum
interactions, including the Chern-gap opening, the exchange-biased effect, the
topological Hall effect and the emergent inductance. We hope this work serves
as a guide for future explorations of quantum magnets.Comment: Submitted versio
Probing topological quantum matter with scanning tunnelling microscopy
The search for topological phases of matter is evolving towards strongly
interacting systems, including magnets and superconductors, where exotic
effects emerge from the quantum-level interplay between geometry, correlation
and topology. Over the past decade or so, scanning tunnelling microscopy has
become a powerful tool to probe and discover emergent topological matter,
because of its unprecedented spatial resolution, high-precision electronic
detection and magnetic tunability. Scanning tunnelling microscopy can be used
to probe various topological phenomena, as well as complement results from
other techniques. We discuss some of these proof-of-principle methodologies
applied to probe topology, with particular attention to studies performed under
a tunable vector magnetic field, which is a relatively new direction of recent
focus. We then project the future possibilities for atomic-resolution
tunnelling methods in providing new insights into topological matter
LLM-FuncMapper: Function Identification for Interpreting Complex Clauses in Building Codes via LLM
As a vital stage of automated rule checking (ARC), rule interpretation of
regulatory texts requires considerable effort. However, interpreting regulatory
clauses with implicit properties or complex computational logic is still
challenging due to the lack of domain knowledge and limited expressibility of
conventional logic representations. Thus, LLM-FuncMapper, an approach to
identifying predefined functions needed to interpret various regulatory clauses
based on the large language model (LLM), is proposed. First, by systematically
analysis of building codes, a series of atomic functions are defined to capture
shared computational logics of implicit properties and complex constraints,
creating a database of common blocks for interpreting regulatory clauses. Then,
a prompt template with the chain of thought is developed and further enhanced
with a classification-based tuning strategy, to enable common LLMs for
effective function identification. Finally, the proposed approach is validated
with statistical analysis, experiments, and proof of concept. Statistical
analysis reveals a long-tail distribution and high expressibility of the
developed function database, with which almost 100% of computer-processible
clauses can be interpreted and represented as computer-executable codes.
Experiments show that LLM-FuncMapper achieve promising results in identifying
relevant predefined functions for rule interpretation. Further proof of concept
in automated rule interpretation also demonstrates the possibility of
LLM-FuncMapper in interpreting complex regulatory clauses. To the best of our
knowledge, this study is the first attempt to introduce LLM for understanding
and interpreting complex regulatory clauses, which may shed light on further
adoption of LLM in the construction domain
Diagnosing the possible chiral superconductivity in SrRuO and beyond using supercurrent
One approach to probe the still controversial superconductivity in
SrRuO is to apply external perturbations that break the underlying
tetragonal crystalline symmetry. Chiral and states
respond to such perturbations in ways that may help to distinguish them from
other superconducting pairings. However, past experimental efforts along this
line, using uniaxial strains and magnetic fields parallel to the RuO plane,
have not been able to reach unambiguous conclusion. In this study, we propose
to diagnose the possible chiral superconducting order in SrRuO using an
alternative tetragonal-symmetry-breaking perturbation -- in-plane supercurrent.
We study the superconducting phase diagram as a function of both temperature
and the applied supercurrent. Supercurrent generically splits the transition of
the two chiral order parameter components, and we show that the splitting can
give rise to visible specific heat anomalies. Furthermore, supercurrent
parallel and anti-parallel to the unidirectional propagation of the chiral edge
modes impact the edge states in different manner. This difference manifests in
tunneling spectrum, thereby providing an additional means to probe the
chirality even when the related spontaneous edge current is vanishingly small.
Finally, we discuss how supercurrent may help to identity other time-reversal
symmetry breaking superconducting states. Our proposal applies to other
candidate chiral superconductors.Comment: 7 pages, 7 figure
Superradiant anomaly magnification in evolution of vector bosonic condensates bounded by a Kerr black hole with near-horizon reflection
Ultralight vector particles can form evolving condensates around a Kerr black
hole (BH) due to superradiant instability. We study the effect of near-horizon
reflection on the evolution of this system; by matching three pieces of
asymptotic expansions of the Proca equation in Kerr metric and considering the
leading order in the electric mode, we present explicit analytical expressions
for the corrected energy level shifts and the superradiant instability rates.
Particularly, in high-spin BH cases, we identify an anomalous situation where
the superadiance rate is temporarily increased by the reflection parameter
, which also occurs in the scalar scenario, but is largely
magnified in vector condensates due to a faster growth rate in dominant mode;
we constructed several featured quantities to illustrate this anomaly, and
formalized the magnification with relevant correction factors, which may be of
significance in future studies of gravitational waveforms of this monochromatic
type. In addition, the duration of superradiance for the whole evolution is
prolonged with a delay factor, which is calculated to be
approximately
Effects of ACE inhibition on endothelial progenitor cell mobilization and prognosis after acute myocardial infarction in type 2 diabetic patients
OBJECTIVE: We aimed to assess the chemotactic response of endothelial progenitor cells to angiotensin-converting enzyme inhibitors in T2DM patients after acute myocardial infarction, as well as the associated prognosis. METHODS: Sixty-eight T2DM patients with acute myocardial infarction were randomized to either receive or not receive daily oral perindopril 4 mg, and 36 non-diabetic patients with acute myocardial infarction were enrolled as controls. The numbers of circulating CD45−/low+CD34+CD133+KDR+ endothelial progenitor cells, as well as the stromal cell-derived factor-α and high-sensitivity C reactive protein levels, were measured before acute percutaneous coronary intervention and on days 1, 3, 5, 7, 14, and 28 after percutaneous coronary intervention. Patients were followed up for 6 months. Chinese Clinical Trial Registry: ChiCTR-TRC-12002599. RESULTS: T2DM patients had lower circulating endothelial progenitor cell counts, decreased plasma vascular endothelial growth factor and α levels, and higher plasma high-sensitivity C reactive protein levels compared with non-diabetic controls. After receiving perindopril, the number of circulating endothelial progenitor cells increased from day 3 to 7, as did the plasma levels of vascular endothelial growth factor and stromal cell-derived factor-α, compared with the levels in T2DM controls. Plasma high-sensitivity C reactive protein levels in the treated group decreased to the same levels as those in non-diabetic controls. Furthermore, compared with T2DM controls, the perindopril-treated T2DM patients had lower cardiovascular mortality and occurrence of heart failure symptoms (
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