The chiral anomaly, Dirac and Weyl semimetals, and force-free magnetic fields

The chiral anomaly is a purely quantum mechanical phenomenon that has a long history dating back to the late 1960s. Surprisingly, it has recently made a macroscopic appearance in condensed matter physics. A brief introduction to the relevant features of this anomaly is given and it is shown that its appearance in condensed matter systems must involve force-free magnetic fields, which may help explain the long current relaxation times in Dirac and Weyl semimetals.

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Ideal diamagnetic response at room temperature by graphene-n-heptane-permalloy system

Modern Physics Letters B ◽

10.1142/s0217984920504151 ◽

2020 ◽

Vol 34 (36) ◽

pp. 2050415

Author(s):

Yasushi Kawashima ◽

Rajendra Dulal ◽

Serafim Teknowijoyo ◽

Sara Chahid ◽

Armen Gulian

Keyword(s):

Magnetic Fields ◽

Graphene Layer ◽

Room Temperature ◽

Condensed Matter ◽

Condensed Matter Physics ◽

Diamagnetic Response ◽

Quantum Phenomenon ◽

The Moment ◽

Three Components

Perfect screening of sub-milligauss magnetic fields (ideal diamagnetism) by a system comprised of a graphene and thin permalloy foil parallel to the graphene layer immersed in [Formula: see text]-heptane is observed at room temperature. The presence of all three components is necessary for the effect to occur. Ideal diamagnetic response appears at the moment of [Formula: see text]-heptane injection and disappears when the liquid evaporates. Until then, no change of diamagnetic moment occurs at further variation of the field. The observed ideal diamagnetic feature is either a footprint of a novel type of superconductivity at room temperature or a yet unknown quantum phenomenon in condensed matter physics.

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Dirac oscillator in a spinning cosmic string spacetime in external magnetic fields: Investigation of the energy spectrum and the connection with condensed matter physics

Physical Review D ◽

10.1103/physrevd.102.105020 ◽

2020 ◽

Vol 102 (10) ◽

Author(s):

Márcio M. Cunha ◽

Henrique S. Dias ◽

Edilberto O. Silva

Keyword(s):

Energy Spectrum ◽

Magnetic Fields ◽

Cosmic String ◽

Condensed Matter ◽

Condensed Matter Physics ◽

Dirac Oscillator

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Topologically Protected Wormholes in Type-III Weyl Semimetal Co3In2X2 (X = S, Se)

Condensed Matter ◽

10.3390/condmat6020018 ◽

2021 ◽

Vol 6 (2) ◽

pp. 18

Author(s):

Christopher Sims

Keyword(s):

Particle Physics ◽

Condensed Matter ◽

Ideal Type ◽

Condensed Matter Physics ◽

Type Iii ◽

Weyl Semimetal ◽

Topological Quantum ◽

Weyl Semimetals ◽

Quantum Materials

The observation of wormholes has proven to be difficult in the field of astrophysics. However, with the discovery of novel topological quantum materials, it is possible to observe astrophysical and particle physics effects in condensed matter physics. It is proposed in this work that wormholes can exist in a type-III Weyl phase. In addition, these wormholes are topologically protected, making them feasible to create and measure in condensed matter systems. Finally, Co3In2X2 (X = S, Se) are identified as ideal type-III Weyl semimetals and experiments are put forward to confirm the existence of a type-III Weyl phase.

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Anomaly Non-renormalization in Interacting Weyl Semimetals

Communications in Mathematical Physics ◽

10.1007/s00220-021-04004-2 ◽

2021 ◽

Author(s):

Alessandro Giuliani ◽

Vieri Mastropietro ◽

Marcello Porta

Keyword(s):

Condensed Matter ◽

Interaction Strength ◽

Lattice Models ◽

Chiral Anomaly ◽

Quasi Particle ◽

Weyl Semimetals ◽

Infrared Limit ◽

Quadratic Response ◽

Relativistic Description ◽

Weyl Fermions

AbstractWeyl semimetals are 3D condensed matter systems characterized by a degenerate Fermi surface, consisting of a pair of ‘Weyl nodes’. Correspondingly, in the infrared limit, these systems behave effectively as Weyl fermions in $$3+1$$ 3 + 1 dimensions. We consider a class of interacting 3D lattice models for Weyl semimetals and prove that the quadratic response of the quasi-particle flow between the Weyl nodes is universal, that is, independent of the interaction strength and form. Universality is the counterpart of the Adler–Bardeen non-renormalization property of the chiral anomaly for the infrared emergent description, which is proved here in the presence of a lattice and at a non-perturbative level. Our proof relies on constructive bounds for the Euclidean ground state correlations combined with lattice Ward Identities, and it is valid arbitrarily close to the critical point where the Weyl points merge and the relativistic description breaks down.

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Inelastic scattering at surfaces and interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143560 ◽

1986 ◽

Vol 44 ◽

pp. 392-393

Author(s):

R. H. Ritchie ◽

A. Howie

Keyword(s):

Inelastic Scattering ◽

Surface Properties ◽

Correlation Energy ◽

Condensed Matter ◽

Charged Particles ◽

Condensed Matter Physics ◽

Optical Phonons ◽

Exchange Correlation ◽

Surfaces And Interfaces ◽

Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

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