80 research outputs found
Higher-order Topology of Axion Insulator EuInAs
Based on first-principles calculations and symmetry analysis, we propose that
EuInAs is a long awaited axion insulator with antiferromagnetic (AFM)
long range order. Characterized by the parity-based invariant ,
the topological magneto-electric effect is quantized with in the
bulk, with a band gap as large as 0.1 eV. When the staggered magnetic moment of
the AFM phase is along axis, it's also a TCI phase. Gapless surface
states emerge on (100), (010) and (001) surfaces, protected by mirror
symmetries (nonzero mirror Chern numbers). When the magnetic moment is along
axis, the (100) and (001) surfaces are gapped. As a consequence of a
high-order topological insulator with , the one-dimensional (1D)
chiral state can exist on the hinge between those gapped surfaces. We have
calculated both the topological surface states and hinge state in different
phases of the system, respectively, which can be detected by ARPES or STM
experiments
Automatic Data Visualization Generation from Chinese Natural Language Questions
Data visualization has emerged as an effective tool for getting insights from
massive datasets. Due to the hardness of manipulating the programming languages
of data visualization, automatic data visualization generation from natural
languages (Text-to-Vis) is becoming increasingly popular. Despite the plethora
of research effort on the English Text-to-Vis, studies have yet to be conducted
on data visualization generation from questions in Chinese. Motivated by this,
we propose a Chinese Text-to-Vis dataset in the paper and demonstrate our first
attempt to tackle this problem. Our model integrates multilingual BERT as the
encoder, boosts the cross-lingual ability, and infuses the -gram information
into our word representation learning. Our experimental results show that our
dataset is challenging and deserves further research
Magnetic Topological Quantum Chemistry
For over 100 years, the group-theoretic characterization of crystalline
solids has provided the foundational language for diverse problems in physics
and chemistry. However, the group theory of crystals with commensurate magnetic
order has remained incomplete for the past 70 years, due to the complicated
symmetries of magnetic crystals. In this work, we complete the 100-year-old
problem of crystalline group theory by deriving the small corepresentations,
momentum stars, compatibility relations, and magnetic elementary band
corepresentations of the 1,421 magnetic space groups (MSGs), which we have made
freely accessible through tools on the Bilbao Crystallographic Server. We
extend Topological Quantum Chemistry to the MSGs to form a complete, real-space
theory of band topology in magnetic and nonmagnetic crystalline solids -
Magnetic Topological Quantum Chemistry (MTQC). Using MTQC, we derive the
complete set of symmetry-based indicators of electronic band topology, for
which we identify symmetry-respecting bulk and anomalous surface and hinge
states.Comment: Final version, 10 pg main text + 184 pg appendix, 5 + 25 figure
A Communication Theory Perspective on Prompting Engineering Methods for Large Language Models
The springing up of Large Language Models (LLMs) has shifted the community
from single-task-orientated natural language processing (NLP) research to a
holistic end-to-end multi-task learning paradigm. Along this line of research
endeavors in the area, LLM-based prompting methods have attracted much
attention, partially due to the technological advantages brought by prompt
engineering (PE) as well as the underlying NLP principles disclosed by various
prompting methods. Traditional supervised learning usually requires training a
model based on labeled data and then making predictions. In contrast, PE
methods directly use the powerful capabilities of existing LLMs (i.e., GPT-3
and GPT-4) via composing appropriate prompts, especially under few-shot or
zero-shot scenarios. Facing the abundance of studies related to the prompting
and the ever-evolving nature of this field, this article aims to (i) illustrate
a novel perspective to review existing PE methods, within the well-established
communication theory framework; (ii) facilitate a better/deeper understanding
of developing trends of existing PE methods used in four typical tasks; (iii)
shed light on promising research directions for future PE methods
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