Subtopic Deep Dive

Weyl Semimetals and Chiral Anomaly
Research Guide

What is Weyl Semimetals and Chiral Anomaly?

Weyl semimetals are topological materials hosting Weyl fermions at band-touching points called Weyl nodes, with the chiral anomaly manifesting as negative magnetoresistance under parallel electric and magnetic fields.

Research identifies Weyl nodes in TaAs-family materials like TaAs and TaP using ARPES and magnetotransport. Negative magnetoresistance in TaAs provides direct evidence of the chiral anomaly (Huang et al., 2015). Over 10 major papers since 2015, including Lv et al. (2015, 1656 citations) and Yan & Felser (2017, 1653 citations), characterize these phenomena.

Curated Papers

Key Challenges

Why It Matters

Weyl semimetals enable novel transport like chiral magnetic effect, observed in ZrTe5 (Li et al., 2016), linking condensed matter to quantum field theory. TaAs shows anomaly-induced negative magnetoresistance (Huang et al., 2015), promising spintronic devices. Ultrahigh mobility in NbP (Shekhar et al., 2015) suggests applications in high-field electronics.

Key Research Challenges

Locating Weyl Nodes

Identifying precise Weyl node positions requires high-resolution ARPES, as in TaAs (Lv et al., 2015). Disorder scatters electrons, complicating detection. Surface Fermi arcs must be distinguished from bulk states (Huang et al., 2015).

Proving Chiral Anomaly

Negative magnetoresistance in TaP lacks well-defined chirality (Arnold et al., 2016). Distinguishing anomaly from classical effects demands low-temperature, high-field measurements. Quantum oscillations interfere with signals (Shekhar et al., 2015).

Impurity Scattering

Non-magnetic impurities broaden Weyl cones, reducing anomaly signatures. TaAs-family materials suffer residual resistivity (Yang et al., 2015). Scaling theory predicts robustness, but experiments show limitations (Huang et al., 2015).

Essential Papers

Experimental Discovery of Weyl Semimetal TaAs

B. Q. Lv, H. M. Weng, B. B. Fu et al. · 2015 · Physical Review X · 1.7K citations

Weyl semimetals are a class of materials that can be regarded as\nthree-dimensional analogs of graphene breaking time reversal or inversion\nsymmetry. Electrons in a Weyl semimetal behave as Weyl f...

Topological Materials: Weyl Semimetals

Binghai Yan, Claudia Felser · 2017 · Annual Review of Condensed Matter Physics · 1.7K citations

Topological insulators and topological semimetals are both new classes of quantum materials, which are characterized by surface states induced by the topology of the bulk band structure. Topologica...

A Weyl Fermion semimetal with surface Fermi arcs in the transition metal monopnictide TaAs class

Shin-Ming Huang, Su‐Yang Xu, Ilya Belopolski et al. · 2015 · Nature Communications · 1.5K citations

Observation of the Chiral-Anomaly-Induced Negative Magnetoresistance in 3D Weyl Semimetal TaAs

Xiaochun Huang, Lingxiao Zhao, Yujia Long et al. · 2015 · Physical Review X · 1.5K citations

Weyl semimetal is the three-dimensional analog of graphene. According to quantum field theory, the appearance of Weyl points near the Fermi level will cause novel transport phenomena related to chi...

Weyl Semimetal Phase in Noncentrosymmetric Transition-Metal Monophosphides

Hongming Weng, Chen Fang, Zhong Fang et al. · 2015 · Physical Review X · 1.4K citations

Based on first principle calculations, we show that a family of nonmagnetic\nmaterials including TaAs, TaP, NbAs and NbP are Weyl semimetal (WSM) without\ninversion center. We find twelve pairs of ...

Negative magnetoresistance without well-defined chirality in the Weyl semimetal TaP

F. Arnold, Chandra Shekhar, Shu-Chun Wu et al. · 2016 · Nature Communications · 1.3K citations

Extremely large magnetoresistance and ultrahigh mobility in the topological Weyl semimetal candidate NbP

Chandra Shekhar, Ajaya K. Nayak, Yan Sun et al. · 2015 · Nature Physics · 1.1K citations

Reading Guide

Foundational Papers

No pre-2015 foundational papers available; start with Lv et al. (2015) for TaAs discovery via ARPES and Weng et al. (2015) for theoretical Weyl pairs prediction.

Recent Advances

Huang et al. (2015) for chiral anomaly evidence; Arnold et al. (2016) on TaP magnetoresistance chirality issues; Yan & Felser (2017) review of topological semimetals.

Core Methods

ARPES maps Weyl nodes and Fermi arcs (Lv et al., 2015); magnetotransport measures negative resistance (Huang et al., 2015); first-principles DFT predicts band topology (Weng et al., 2015).

How PapersFlow Helps You Research Weyl Semimetals and Chiral Anomaly

Discover & Search

Research Agent uses searchPapers('Weyl semimetal TaAs chiral anomaly') to retrieve Lv et al. (2015), then citationGraph reveals 1656 citing works including Huang et al. (2015); findSimilarPapers on TaAs expands to TaP studies (Arnold et al., 2016); exaSearch queries 'negative magnetoresistance Weyl' for magnetotransport evidence.

Analyze & Verify

Analysis Agent applies readPaperContent on Huang et al. (2015) to extract magnetoresistance data, verifyResponse with CoVe cross-checks chiral anomaly claims against Lv et al. (2015), and runPythonAnalysis fits resistivity curves using NumPy for anomaly confirmation; GRADE scores evidence strength on ARPES node detection.

Synthesize & Write

Synthesis Agent detects gaps in Weyl superconductivity post-TaAs papers, flags contradictions between TaP chirality results (Arnold et al., 2016); Writing Agent uses latexEditText for band structure figures, latexSyncCitations integrates 10+ references, latexCompile generates polished review; exportMermaid diagrams Weyl node pairs from Weng et al. (2015).

Use Cases

"Plot negative magnetoresistance data from TaAs chiral anomaly papers"

Research Agent → searchPapers → Analysis Agent → readPaperContent(Huang 2015) → runPythonAnalysis(NumPy fit resistivity vs B-field) → matplotlib plot of anomaly signature.

"Write LaTeX section on Weyl nodes in TaAs-family with citations"

Research Agent → citationGraph(Lv 2015) → Synthesis Agent → gap detection → Writing Agent → latexEditText(draft) → latexSyncCitations(10 papers) → latexCompile(PDF review section).

"Find GitHub repos analyzing ARPES data for Weyl semimetals"

Research Agent → searchPapers(ARPES TaAs) → Code Discovery → paperExtractUrls → paperFindGithubRepo → githubRepoInspect → exportCsv of analysis scripts for node fitting.

Automated Workflows

Deep Research workflow scans 50+ TaAs papers via searchPapers → citationGraph, producing structured report on anomaly evidence with GRADE scores. DeepScan's 7-step chain verifies magnetoresistance in Huang et al. (2015) using CoVe checkpoints and Python curve fitting. Theorizer generates hypotheses on Weyl superconductivity gaps from Lv et al. (2015) synthesis.

Try Doxa for Weyl Semimetals and Chiral Anomaly Research

Frequently Asked Questions

What defines Weyl semimetals?

Weyl semimetals host linear band crossings at Weyl nodes without inversion or time-reversal symmetry, analogous to 3D graphene (Lv et al., 2015).

How is chiral anomaly detected experimentally?

Negative magnetoresistance under parallel E and B fields in TaAs evidences the anomaly (Huang et al., 2015); ARPES confirms Weyl nodes and Fermi arcs (Huang et al., 2015).

What are key papers on TaAs Weyl semimetal?

Lv et al. (2015, Phys. Rev. X, 1656 citations) discovered TaAs Weyl semimetal; Huang et al. (2015) observed chiral anomaly; Weng et al. (2015) predicted 12 Weyl pairs.

What are open problems in Weyl semimetals?

Resolving chirality ambiguity in TaP magnetoresistance (Arnold et al., 2016); realizing Weyl superconductivity; reducing impurity effects on transport (Shekhar et al., 2015).