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Related papers: On the trace anomaly for Weyl fermions

200 papers

One of the interesting features about field theories in odd dimensions is the induction of parity violating terms and well-defined {\em finite} topological actions via quantum loops if a fermion mass term is originally present and…

High Energy Physics - Theory · Physics 2015-06-26 R. Delbourgo , A. B. Waites

The conformal anomaly (also known as the stress-energy trace anomaly) of an interacting quantum theory, associated with violation of Weyl (conformal) symmetry by quantum effects, can be amended if one endows the theory with a dilatation…

General Relativity and Quantum Cosmology · Physics 2017-09-04 Stefano Lucat , Tomislav Prokopec

The low-energy quasiparticles of Weyl semimetals are a condensed-matter realization of the Weyl fermions introduced in relativistic field theory. Chiral anomaly, the nonconservation of the chiral charge under parallel electric and magnetic…

Materials Science · Physics 2017-12-29 Pilkwang Kim , Ji Hoon Ryoo , Cheol-Hwan Park

Conformally invariant quantum field theories develop trace anomalies when defined on curved backgrounds. We study again the problem of identifying all possible trace anomalies in d=6 by studying the consistency conditions to derive their 10…

High Energy Physics - Theory · Physics 2009-10-31 F. Bastianelli , G. Cuoghi , L. Nocetti

We present a field theoretical model of anomalous transport in Weyl semi-metals. We calculate the Chiral Magnetic and Chiral Vortical Effect in the electric, axial (valley) and energy current. Our findings coincide with the results of a…

High Energy Physics - Theory · Physics 2014-02-26 Karl Landsteiner

Weyl fermions are one of the simplest objects that link ideas in geometry and topology to highenergy physics and condensed matter physics. Although the existence of Weyl fermions as elementary particles remains dubious, there is mounting…

Mesoscale and Nanoscale Physics · Physics 2024-06-05 Azaz Ahmad , Gautham Varma K. , Gargee Sharma

Weyl semimetals are well-known for hosting topologically protected linear band crossings, serving as the analog of the relativistic Weyl Fermions in the condensed matter context. Such analogy persists deeply, allowing the existence of the…

Mesoscale and Nanoscale Physics · Physics 2024-02-15 Yang Gao

We discover three-dimensional intertwined Weyl phases, by developing a theory to create topological phases. The theory is based on intertwining existing topological gapped and gapless phases protected by the same crystalline symmetry. The…

Mesoscale and Nanoscale Physics · Physics 2022-02-09 W. B. Rui , Zhen Zheng , Moritz M. Hirschmann , Song-Bo Zhang , Chenjie Wang , Z. D. Wang

We review the parity anomaly and a duality web in 2+1 dimensions. An odd dimensional non-interacting Dirac fermion theory is not parity invariant at quantum level. We demonstrate the parity anomaly in a three dimensional non-interacting…

High Energy Physics - Theory · Physics 2018-08-29 Chen-Te Ma

Chiral anomaly is a key feature of Lorentz-invariant quantum field theories: in presence of parallel external electric and magnetic fields, the number of massless Weyl fermions of a given chirality is not conserved. In condensed matter,…

Strongly Correlated Electrons · Physics 2026-02-20 Shantonu Mukherjee , Sayantan Sharma , Hridis K. Pal

Witten's anomaly for SU(2) with a single I=1/2 Weyl fermion in four dimension is shown to be reproduced by the lattice overlap. The mechanism is based on Berry's phase, and on the analyticity of the matrix $H$ by which the overlap is…

High Energy Physics - Lattice · Physics 2016-09-01 Herbert Neuberger

The recent discovery of Weyl fermions in solids enables exploitation of relativistic physics and development of a spectrum of intriguing physical phenomena. They are constituted of pairs of Weyl points with two-fold band degeneracy, which…

The discovery of a chiral anomaly in Weyl semimetals, the non-conservation of chiral charge and energy across two opposite chirality Weyl nodes, has sparked immense interest in understanding its impact on various physical phenomena. Here,…

Mesoscale and Nanoscale Physics · Physics 2023-07-19 Sunit Das , Kamal Das , Amit Agarwal

Motivated by the search for possible CP violating terms in the trace of the energy-momentum tensor in theories coupled to gravity we revisit the problem of trace anomalies in chiral theories. We recalculate the latter and ascertain that in…

High Energy Physics - Theory · Physics 2015-06-19 Loriano Bonora , Stefano Giaccari , Bruno Lima de Souza

In this paper, we investigate the Pontryagin trace anomaly for chiral fermions in a general curved background using Pauli-Villars regularization. We use both Feynman diagram method and Fujikawa's method to calculate the parity-odd…

High Energy Physics - Theory · Physics 2025-02-11 Chang-Yong Liu

The Weyl semimetals represent a distinct category of topological materials wherein the low-energy excitations appear as the long-sought Weyl fermions. Exotic transport and optical properties are expected because of the chiral anomaly and…

We begin this review with an introduction and a discussion of Weyl fermions as emergent particles in condensed matter systems, and explain how high energy phenomena like the chiral anomaly can be seen in low energy experiments. We then…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 Sumathi Rao

The phenomenon of unpaired Weyl fermions appearing on the sole 2n-dimensional boundary of a (2n+1)-dimensional manifold with massive Dirac fermions was recently analyzed in a companion paper by one of the authors. In this Letter we show…

High Energy Physics - Lattice · Physics 2024-03-15 David B. Kaplan , Srimoyee Sen

The Weyl equation describes chiral massless relativistic particles, called Weyl fermions, which have important relations to neutrinos. A direct observation of the dynamics of Weyl fermions in an experiment is difficult to achieve. This…

Quantum Physics · Physics 2019-04-05 De-Sheng Li , Chun-Wang Wu , Lin-Ze He , Wei Wu , Ping-Xing Chen

We show that there exists a generalized, universal notion of the trace anomaly for theories which are not conformally invariant at the classical level. The definition is suitable for any regularization scheme and clearly states to what…

High Energy Physics - Theory · Physics 2024-02-16 Renata Ferrero , Sebastián A. Franchino-Viñas , Markus B. Fröb , William C. C. Lima