Semiclassical theory of anomalous transport in type-II topological Weyl semimetals

McCormick, Timothy M.; McKay, Robert C.; Trivedi, Nandini

doi:10.1103/physrevb.96.235116

Cited by 28 publications

(28 citation statements)

References 80 publications

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“…A semiclassical formulation of anomalous Hall effect [9] is laborious, because the concept of Berry connection (or the 'anomalous velocity' [10]) is based on off-diagonal matrix elements linking adjacent Bloch functions and not wave packets of semi-classical transport theory [9]. This makes any intuitive picture of how Berry curvature combined to a longitudinal thermal gradient can produce a transverse electric field (an anomalous Nernst response) [7,11] or a transverse thermal gradient (an anomalous thermal Hall response) [12,13] even more challenging.…”

Section: Introductionmentioning

confidence: 99%

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

et al. 2020

Sci. Adv.

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The Wiedemann-Franz (WF) law links the ratio of electronic charge and heat conductivity to fundamental constants. It has been tested in numerous solids, but the extent of its relevance to the anomalous transverse transport, which represents the topological nature of the wave function, remains an open question. Here we present a study of anomalous transverse response in the noncollinear antiferromagnet Mn3Ge extended from room temperature down to sub-Kelvin temperature and find that the anomalous Lorenz ratio remains close to the Sommerfeld value up to 100 K, but not above. The finite-temperature violation of the WF correlation is caused by a mismatch between the thermal and electrical summations of the Berry curvature, rather than the inelastic scattering as observed in ordinary metals. This interpretation is backed by our theoretical calculations, which reveals a competition between the temperature and the Berry curvature distribution. The accuracy of the experiment is supported by the verification of the Bridgman relation between the anomalous Ettingshausen and Nernst effects. Our results identify the anomalous Lorenz ratio as an extremely sensitive probe of Berry spectrum near the chemical potential. arXiv:1812.04339v3 [cond-mat.str-el]

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Section: Introductionmentioning

confidence: 99%

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

et al. 2020

Sci. Adv.

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“…In type-I WSM, there is a closed Fermi surface enclosing either an electron or a hole pocket, with the vanishing density of states at the Weyl point. However, in type-II WSM, there are unbounded electron and hole pockets at the Fermi surface, and there are a large density of states even at the Weyl point [14], which results in different magnetotransport properties of type-II WSM [22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Linear magnetochiral transport in tilted type-I and type-II Weyl semimetals

Das

Agarwal

2019

Phys. Rev. B

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Berry curvature in Weyl semimetals leads to intriguing magnetoconductivity and magneto-thermal transport properties. Here, we explore the impact of the tilting of the Weyl nodes, on the magnetoconductivity of type-I and type-II Weyl semimetals using the Berry curvature connected Boltzmann transport formalism. We find that in addition to the quadratic magnetic field (B) corrections induced by the tilt, there are also anisotropic and B-linear corrections in several elements of the conductivity matrix. For the case of magnetic field applied perpendicular to the tilt direction, we show the existence of previously unexplored B-linear transverse conductivity components. For the other case of magnetic field applied parallel to the tilt axis, the B-linear corrections appear in the longitudinal conductivity giving rise to anisotropic magnetoresistance measurements. Our systematic analysis of the full magnetoconductivity matrix, predicts several specific experimental signatures related to the tilting of the Weyl nodes in both type-I and type-II Weyl semimetals. * kamaldas@iitk.ac.in †

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“…Interestingly, the Weyl nodes act as a source or sink of Berry curvature (BC), which in turn acts as a fictitious magnetic field in the momentum space 19,20 . This leads to the possibility of several interesting transport phenomena in isotropic and tilted WSMs [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] . Several of these have also been experimentally demonstrated 5,7,[35][36][37][38][39][40][41][42][43][44][45][46][47][48] .…”

Section: Introductionmentioning

confidence: 99%

Berry curvature induced thermopower in type-I and type-II Weyl semimetals

Das

Agarwal

2019

Phys. Rev. B

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Berry curvature acts analogously to a magnetic field in the momentum-space, and it modifies the flow of charge carriers and entropy. This induces several intriguing magnetoelectric and magnetothermal transport phenomena in Weyl semimetals. Here, we explore the impact of the Berry curvature and orbital magnetization on the thermopower in tilted type-I and type-II Weyl semimetals, using semiclassical Boltzmann transport formalism. We analytically calculate the full magnetoconductivity matrix and use it to obtain the thermopower matrix for different orientations of the magnetic field (B), with respect to the tilt axis. We find that the tilt of the Weyl nodes induces linear magnetic field terms in the conductivity matrix, as well as in the thermopower matrix. The linear-B term appears in the Seebeck coefficients, when the B-field is applied along the tilt axis. Applying the magnetic field in a plane perpendicular to the tilt axis results in a quadratic-B planar Nernst effect, linear-B out-of-plane Nernst effect and quadratic-B correction in the Seebeck coefficient. arXiv:1903.01205v3 [cond-mat.mes-hall]

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Semiclassical theory of anomalous transport in type-II topological Weyl semimetals

Cited by 28 publications

References 80 publications

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

Linear magnetochiral transport in tilted type-I and type-II Weyl semimetals

Berry curvature induced thermopower in type-I and type-II Weyl semimetals

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