Geometric treatment of conduction electron scattering by crystal lattice strains and dislocations

Viswanathan, Koushik; Chandrasekar, Srinivasan

doi:10.1063/1.4904934

Cited by 10 publications

(4 citation statements)

References 48 publications

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“…On the other hand, if the nonlocal transport is negligible, R 12,34 < R 12,3 ′ 4 ′ is observed, it is the fingerprint of the chiral current due to the TCME. The effect can be discriminated from any previously reported conventional transport induced by dislocation [58,[61][62][63][64][65][66][67][68][69].…”

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confidence: 99%

Torsional Chiral Magnetic Effect in a Weyl Semimetal with a Topological Defect

2016

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We propose a torsional response raised by lattice dislocation in Weyl semimetals akin to chiral magnetic effect; i.e. a fictitious magnetic field arising from screw or edge dislocation induces charge current. We demonstrate that, in sharp contrast to the usual chiral magnetic effect which vanishes in real solid state materials, the torsional chiral magnetic effect exists even for realistic lattice models, which implies the experimental detection of the effect via SQUID or nonlocal resistivity measurements in Weyl semimetal materials. 11.30.Rd, 11.15.Yc Recently, many candidate materials for Dirac semimetals and Weyl semimetals (WSMs) [1][2][3][4], have been discovered [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. These topological semimetals are intriguing because of exotic transport phenomena associated with the chiral anomaly in quantum field theory [24], such as the anomalous Hall effect [25,26], chiral magnetic effect (CME) [27], negative longitudinal magnetoresistance [5, 12, 19-21, 28, 29], and chiral gauge field [30].Among them, the CME has been discussed in broad areas of quantum many-body physics, including nuclear and nonequilibrium physics as well as condensed matter physics. It is the generation of charge current parallel to an applied magnetic field even in the absence of electric fields. In nuclear physics, together with the chiral vortical effect [31], it is expected to play an important role in heavy ion collisions experiments [32,33]. The CME also caused a stir in nonequilibrium statistical physics, since it leads to the existence of the ground state which, recently, attracts a renewed interest in connection with the realization of quantum time crystal [34], and then the CME has been studied from this point of view [35,36]. However, unfortunately, their results are negative for its realization: the macroscopic ground state current in realistic WSMs is always absent.In this letter, we propose a chiral response in WSMs, named "torsional chiral magnetic effect (TCME)", in which the ground state charge current is caused by the effective magnetic field induced by lattice dislocation as shown in FIG.1. By using the Cartan formalism of the differential geometry, we can describe the lattice strain and dislocation in terms of vielbein and torsion [37]. From the viewpoint of the quantum field theory in curved space-time, the TCME is raised by the mixed action of electromagnetic and torsional fields that is prohibited in four-dimensional spacetime with the Lorentz symmetry, but made possible in non-relativistic band electrons in solid state systems. Furthermore, we demonstrate that the TCME is possible in realistic lattice models by carrying out numerical calculations. Our results imply the existence of experimentally observable current induced by the TCME in real WSM materials. We also resolve the relation between our results and the no-go theorem that the CME is absent in equilibrium states [35,36]. First of all, we clarify the notations. The indices i, j, · · · = x, y, z a...

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confidence: 99%

Torsional Chiral Magnetic Effect in a Weyl Semimetal with a Topological Defect

2016

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“…For the detail study of the torsion effects we refer to Refs. [21][22][23]. We think that our treatment is still valid if the antisymmetric part of the connection is induced in Eq.…”

Section: Discussionmentioning

confidence: 94%

Low-energy quantum scattering induced by graphene ripples

Liu

Chen

et al. 2015

Physics Letters A

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We report a quantum study of the carrier scattering induced by graphene ripples. Crucial differences between the scattering induced by the ripple and ordinary scattering were found. In contrast to the latter, in which the Born approximation is valid for high-energy process, the former is valid for the low-energy process with a quite broad energy range. Furthermore, in polar symmetry ripples, the scattering amplitude exhibits a pseudo-spin structure, an additional factor $\cos\theta/2$, which leads to an absence of backward scattering. We also elucidate that the scattering cross sections are proportional to the energy cubed of the incident carrier

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“…It has been investigated that the threading dislocations (TDs) are the major cause of limiting the low field mobility at room temperature and higher electron concentration. [29][30][31][32][33][34][35][36][37][38][39][40] The nitrogen (N) and In-vacancies at the dislocation sites in InN create coulomb scattering centers, screening the carrier motion and ultimately decreasing the bulk electron mobility. [41][42][43] Therefore, the reduction of the TD is crucial to achieve high electron mobility.…”

Section: Introductionmentioning

confidence: 99%

Growth of High Mobility InN Film on Ga‐Polar GaN Substrate by Molecular Beam Epitaxy for Optoelectronic Device Applications

Imran

Sulaman

Yousaf

et al. 2022

Adv Materials Inter

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The fabrication of high‐speed electronic and communication devices has rapidly grown the demand for high mobility semiconductors. However, their high cost and complex fabrication process make them less attractive for the consumer market and industrial applications. Indium nitride (InN) can be a potential candidate to fulfill industrial requirements due to simple and low‐cost fabrication process as well as unique electronic properties such as narrow direct bandgap and high electron mobility. In this work, 3 µm thick InN epilayer is grown on (0001) gallium nitride (GaN)/Sapphire template under In‐rich conditions with different In/N flux ratios by molecular beam epitaxy. The sharp InN/GaN interface monolayers with the In‐polar growth are observed, which assure the precise control of the growth parameters. The directly probed electron mobility of 3610 cm2 V‐1 s‐1 is measured with an unintentionally doped electron density of 2.24 × 1017 cm‐3. The screw dislocation and edge dislocation densities are calculated to be 2.56 × 108 and 0.92 × 1010 cm‐2, respectively. The step‐flow growth with the average surface roughness of 0.23 nm for 1 × 1 µm2 is confirmed. The high quality and high mobility InN film make it a potential candidate for high‐speed electronic/optoelectronic devices.

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Geometric treatment of conduction electron scattering by crystal lattice strains and dislocations

Cited by 10 publications

References 48 publications

Torsional Chiral Magnetic Effect in a Weyl Semimetal with a Topological Defect

Torsional Chiral Magnetic Effect in a Weyl Semimetal with a Topological Defect

Low-energy quantum scattering induced by graphene ripples

Growth of High Mobility InN Film on Ga‐Polar GaN Substrate by Molecular Beam Epitaxy for Optoelectronic Device Applications

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