Pith. sign in

REVIEW 5 minor 82 references

Angular Momentum Transfer in Magnetic Weyl Semimetal Spheres

T0 review · 0 major / 5 minor · reviewed 2026-07-30 · grok-4.5

Pith's one-line read A magnetic Weyl-semimetal sphere stores more electromagnetic angular momentum than a topological insulator and spins faster when a nearby point charge is moved slowly.

desk verdict Clean analytic extension of the axion Feynman-disk setup to a WSM sphere, with a real TI correction and a larger predicted mechanical response under standard idealizations. read the letter →

arxiv 2607.27086 v1 pith:B5QCNOXU submitted 2026-07-29 cond-mat.mes-hall cond-mat.mtrl-sci

classification cond-mat.mes-hallcond-mat.mtrl-sci PACS 73.20.Mf03.50.De75.85.+t
keywords axionelectrodynamicsWeylsemimetalelectromagneticangularmomentumFeynmandiskparadoxtopologicalmagnetoelectriceffectquasi-statictorquenanosphere
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper shows that a spherical magnetic Weyl semimetal near a point charge holds a sizable electromagnetic angular momentum coming from axion electrodynamics. When the charge is displaced slowly along the axis, that field angular momentum is converted into ordinary mechanical spin of the sphere, producing a calculable angular velocity and rotation angle. The same geometry for a topological insulator yields a weaker effect. The authors give closed-form multipole series for both cases and estimate that a nanosphere under a charged AFM tip can reach milliradian-per-second speeds and several-degree displacements for the Weyl material, offering a laboratory route to see topological magnetoelectric response as mechanical rotation.

What carries the argument

First-order perturbative solution of the static axion Maxwell equations inside the Weyl sphere (parameter η = 2α b R/π), which produces non-harmonic magnetic multipoles that couple electric harmonics of orders n ± 1 and feed the Abraham angular-momentum integral.

What would settle it

Measure the rotation angle of a levitated or AFM-mounted Weyl nanosphere while a charged tip is displaced quasi-statically along the axis; the observed angle must match the predicted ϑ(t₁) within the stated parameter range or the transfer claim fails.

Watch

Extended reading notes

Core claim

For a magnetic Weyl-semimetal sphere of radius R with a point charge q = Ne at distance d > R, the electromagnetic angular momentum is L_em = (κ/π) N² α² ℏ Λ Ž with κ = 2bR and Λ_WSM an even-power series in R/d; quasi-static motion of the charge then yields a mechanical angular velocity ω(t₁) = (15/(8π R⁵ D))[L_em_z(d₀) − L_em_z(d₁)] that substantially exceeds the corresponding topological-insulator result.

Load-bearing premise

The torque on the sphere is taken to be exactly minus the time derivative of the static field angular momentum under the Abraham prescription, assuming the charge moves slowly enough that radiation, damping and background torques can be ignored.

Editorial extensions

If this is right

  • Weyl nanospheres rotate faster and farther than topological-insulator spheres of equal size and dielectric constant under the same charge motion.
  • The leading far-field angular momentum scales as (R/d)^4 for the Weyl case versus (R/d)^5 for the insulator, so the enhancement grows with separation.
  • A colloidal-probe AFM tip with N ~ 10^4 charges on a 150 nm sphere can produce milliradian-per-second speeds and degree-scale angles, within reach of levitated-optomechanics readouts.
  • The internal non-harmonic magnetic potential is an observable bulk signature of the spatially varying axion field that is absent in topological insulators.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The same multipole machinery could be reused for other axion-response geometries (cylinders, slabs) to map how topology converts stored field momentum into rigid-body motion.
  • If rotational damping and optical restoring torques can be calibrated independently, the measured torque spectrum would give a direct mechanical readout of the bulk Weyl-node separation 2b.
  • Opposite-sign angular momenta for Weyl versus insulator spheres suggest a differential experiment that cancels common-mode electrostatic backgrounds.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

0 major / 5 minor

Summary. The manuscript studies electromagnetic angular momentum stored by a magnetic Weyl-semimetal (WSM) sphere in the presence of an external point charge, within axion electrodynamics. Working to first order in the dimensionless magnetoelectric coupling η = 2α b R/π, the authors obtain closed-form multipole coefficients for the electric and magnetic scalar potentials, evaluate the Abraham field angular momentum L_em, and compare it with the topological-insulator (TI) sphere (revisiting and correcting an earlier TI result). They then show that a quasi-static displacement of the charge converts stored field angular momentum into mechanical rotation of the sphere, deriving analytic expressions for the acquired angular velocity and angular displacement and arguing that both are substantially larger for a WSM than for a TI.

Significance. The work supplies a clean, analytically tractable topological analogue of Feynman’s disk paradox. Strengths include: (i) a controlled perturbative solution of the static axion Maxwell equations with explicit multipole matching; (ii) fully closed-form expressions for L_em (Eqs. 31–34) and for the mechanical response (Eqs. 44–47), with intermediate steps collected in appendices that permit direct verification; (iii) a transparent correction of the prior TI baseline (Ref. [56]), including the previously omitted internal contribution and the proper (R/d)^5 asymptotics; and (iv) a parameter-free comparison showing an enhancement of both Λ and |∂_d Λ| in the WSM relative to the TI. The results are falsifiable in principle via levitated-optomechanics or AFM-tip geometries, and the idealizations (Abraham momentum, adiabatic expansion) are standard for this class of thought experiments and are flagged by the authors.

minor comments (5)
  1. [Fig. 3] Fig. 3 axis labels and legends appear to have encoding artifacts (e.g. “¤WSM”, “" = 5:0”). Please regenerate the figure with proper Λ and ε symbols for production.
  2. [Sec. V, Eqs. (38)–(43)] In Sec. V the identification τ_sphere = −ḋ ∂L_em_0/∂d is standard under the Abraham + adiabatic assumptions, but a one-sentence reminder that Minkowski momentum would redistribute the split between field and matter (without changing total L) would help non-specialist readers.
  3. [Sec. V, Table I] Table I quotes ω ∼ 10^{-3} rad/s and ϑ ∼ 5.8° for the WSM with N ∼ 10^4. A brief note on how sensitive these numbers are to N^2 (and to the choice of 2bR) would make the experimental outlook clearer without expanding scope.
  4. [Sec. IV–V] The phrase “significantly enhanced” is used several times; citing the asymptotic ratio |∂_d Λ_WSM|/∂_d Λ_TI ≈ (36/25)(2ε+3)/(ε+2)(d/R) (Eq. 36) once in the main text would make the claim quantitative at a glance.
  5. [Sec. II] Minor typographical consistency: “axion Maxwell’s equa tions” (header of Sec. II) and occasional spacing around Θ/η subscripts should be cleaned in proof.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: L_em and the mechanical transfer formulae are derived from axion Maxwell equations and multipole matching, not forced by definition or self-citation.

full rationale

The derivation chain is self-contained and non-circular. Section II starts from the standard axion Lagrangian and modified constitutive relations. Section III solves the static axion Maxwell equations for a WSM sphere plus point charge via a controlled expansion in η = 2αbR/π, matching multipole coefficients at the boundary; the TI comparison uses the known bi-isotropic sphere solution (Lindell; Qi et al.), expanded to the same order. Section IV evaluates the Abraham angular momentum integral from those potentials, yielding the closed series for Λ_WSM and the corrected Λ_TI. Section V obtains the mechanical torque from total-angular-momentum conservation under a quasi-static adiabatic expansion (τ_sphere = −ḋ ∂L_em_0/∂d), then integrates for ω and ϑ. Material parameters (ε, b, R, D) enter as external inputs; nothing is fitted to produce the WSM/TI enhancement. Self-citations (prior plasmon work) are background only and do not underwrite the new formulae. No step reduces the claimed prediction to its own input by construction.

Assumptions & free parameters 2 free parameters · 5 assumptions · 0 invented entities

The central claim rests on standard axion electrodynamics for TIs and magnetic WSMs, the Abraham momentum density, the quasi-static adiabatic expansion, and the rigid-body moment of inertia of a uniform sphere. No new particles or forces are postulated; material parameters are taken from the experimental literature. The only modeling choices that are not forced by prior theory are the Abraham (vs Minkowski) prescription and the strict neglect of radiative and damping torques.

free parameters (2)
  • η = 2α b R / π (perturbative expansion parameter) = ∼0.02–0.2 for R∼100 nm
    Treated as small (∼0.02–0.2) to justify truncation at O(η); the numerical window is estimated from typical WSM values but is not fitted to any angular-momentum data.
  • Experimental estimate inputs (N, ε, R, 2bR, d₀, Δd, D, t₁) = N∼10^4, ε=10, R=150 nm, 2bR=75, d₀=600 nm, Δd=10 µm, D=6×10³ kg/m³, t₁=100 s
    Chosen by hand for Table I to illustrate magnitude; not adjusted to match any measurement. Central analytic claims do not depend on these values.
assumptions (5)
  • domain assumption Low-energy electromagnetic response of magnetic WSMs is described by the axion term with Θ_WSM = 2b·r (b₀=0)
    Invoked in Sec. II, Eq. (9); standard effective-field-theory result from the literature (Zyuzin–Burkov et al.).
  • domain assumption Abraham momentum density p_em = (1/4πc) E×H is the correct mechanical momentum density in the medium
    Adopted explicitly in Sec. IV; the Abraham–Minkowski controversy is acknowledged by citation but not re-examined.
  • domain assumption Quasi-static motion (t₁ large) permits adiabatic expansion of the fields and neglect of radiation
    Sec. V, Eqs. (37)–(41); standard for Feynman-paradox analyses but unquantified here.
  • ad hoc to paper Sphere is a rigid body with I = (2/5)MR² free to rotate about z with no external restoring torque
    Sec. V; idealization required to convert torque into ω and ϑ; real levitated or substrate-mounted spheres have additional torques.
  • standard math Matching conditions and multipole expansions of ordinary electrostatics remain valid at leading order in η
    Secs. III–IV; standard Jackson-type boundary-value analysis.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Angular Momentum Transfer in Magnetic Weyl Semimetal Spheres." pith.science (2026). https://pith.science/paper/B5QCNOXU

@misc{pith2026260727086,
  author       = {Pith},
  title        = {Pith review of: Angular Momentum Transfer in Magnetic Weyl Semimetal Spheres},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/B5QCNOXU}},
  note         = {Machine review of arXiv:2607.27086}
}
read the original abstract

In this work, we investigate the problem of electromagnetic angular momentum within the framework of topological materials, described by axion electrodynamics. Specifically, we calculate the electromagnetic angular momentum for a spherical sample of magnetic Weyl semimetal in the presence of a point charge. We then analyze how, by moving the point charge quasi-statically, the angular momentum stored in the electromagnetic field can be converted into mechanical angular momentum of the sphere. Finally, we derive analytical expressions for the resulting angular velocity and angular displacement, demonstrating that the effect is enhanced in the Weyl semimetal compared with a topological insulator.

Figures

Figures reproduced from arXiv: 2607.27086 by the authors.

Figure 1
Figure 1. FIG. 1. Schematic illustration of Feynman’s disk para [PITH_FULL_IMAGE:figures/full_fig_p001_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Geometry of the system. A WSM sphere of ra [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. (a) Dimensionless factor Λ [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

82 extracted references

  1. [56]

    Chyzhykova, J

    A. Chyzhykova, J. van den Brink, and F. S. Nogueira, Feynman paradox in a spherical axion insulator, Phys. Rev. B113, 115414 (2026)

  2. [1]

    J. D. Jackson,Classical electrodynamics, 3rd ed. (Wiley, New York, 1999)

  3. [2]

    R. P. Feynman, R. B. Leighton, and M. Sands,The Feyn- 12 man Lectures on Physics Vol. II(Basic Books, New Mil- lennium Edition, New York, 2011)

  4. [3]

    E. M. Pugh and G. E. Pugh, Physical Significance of the Poynting Vector in Static Fields, American Journal of Physics35, 153–156 (1967)

  5. [4]

    Corinaldesi, Angular momentum of a static electro- magnetic field, American Journal of Physics48, 83–83 (1980)

    E. Corinaldesi, Angular momentum of a static electro- magnetic field, American Journal of Physics48, 83–83 (1980)

  6. [5]

    J. M. Aguirregabiria and A. Hernandez, The Feynman paradox revisited, European Journal of Physics2, 168 (1981)

  7. [6]

    G. G. Lombardi, Feynman’s disk paradox, American Journal of Physics51, 213–214 (1983)

  8. [7]

    Bahder and J

    T. Bahder and J. Sak, Elementary solution to Feynman’s disk paradox, American Journal of Physics53, 495–497 (1985)

Show all 82 references
  1. [8]

    Pantazis and L

    G. Pantazis and L. Perivolaropoulos, A general realis- tic treatment of the disk paradox, European Journal of Physics38, 015204 (2017)

  2. [9]

    J. L. Jim´ enez, I. Campos, and J. A. E. Roa-Neri, The Feynman paradox and hidden momentum, European Journal of Physics43, 055202 (2022)

  3. [10]

    M. Z. Hasan and C. L. Kane, Colloquium: Topological insulators, Rev. Mod. Phys.82, 3045–3067 (2010)

  4. [11]

    Qi and S.-C

    X.-L. Qi and S.-C. Zhang, Topological insulators and su- perconductors, Rev. Mod. Phys.83, 1057–1110 (2011)

  5. [12]

    Yan and C

    B. Yan and C. Felser, Topological Materials: Weyl Semimetals, Annual Review of Condensed Matter Physics8, 337–354 (2017)

  6. [13]

    M. Z. Hasan, S.-Y. Xu, I. Belopolski, and S.-M. Huang, Discovery of Weyl Fermion Semimetals and Topological Fermi Arc States, Annual Review of Condensed Matter Physics8, 289–309 (2017)

  7. [14]

    N. P. Armitage, E. J. Mele, and A. Vishwanath, Weyl and Dirac semimetals in three-dimensional solids, Rev. Mod. Phys.90, 015001 (2018)

  8. [15]

    Weyl, Electron and Gravitation

    H. Weyl, Electron and Gravitation. 1. (In German), Z. Phys.56, 330–352 (1929)

  9. [16]

    Maggiore,A Modern Introduction to Quantum Field Theory(Oxford University Press, Oxford, 2004)

    M. Maggiore,A Modern Introduction to Quantum Field Theory(Oxford University Press, Oxford, 2004)

  10. [17]

    M. V. Berry, Quantal phase factors accompanying adia- batic changes, Proceedings of the Royal Society of Lon- don. A. Mathematical and Physical Sciences392, 45–57 (1984)

  11. [18]

    Xiao, M.-C

    D. Xiao, M.-C. Chang, and Q. Niu, Berry phase effects on electronic properties, Rev. Mod. Phys.82, 1959–2007 (2010)

  12. [19]

    Nielsen and M

    H. Nielsen and M. Ninomiya, Absence of neutrinos on a lattice: (I). Proof by homotopy theory, Nuclear Physics B185, 20–40 (1981)

  13. [20]

    Nielsen and M

    H. Nielsen and M. Ninomiya, Absence of neutrinos on a lattice: (II). Intuitive topological proof, Nuclear Physics B193, 173–194 (1981)

  14. [21]

    X. Wan, A. M. Turner, A. Vishwanath, and S. Y. Savrasov, Topological semimetal and Fermi-arc surface states in the electronic structure of pyrochlore iridates, Phys. Rev. B83, 205101 (2011)

  15. [22]

    Yang, Y.-M

    K.-Y. Yang, Y.-M. Lu, and Y. Ran, Quantum Hall effects in a Weyl semimetal: Possible application in pyrochlore iridates, Phys. Rev. B84, 075129 (2011)

  16. [23]

    A. A. Burkov and L. Balents, Weyl Semimetal in a Topo- logical Insulator Multilayer, Phys. Rev. Lett.107, 127205 (2011)

  17. [24]

    A. A. Burkov, M. D. Hook, and L. Balents, Topological nodal semimetals, Phys. Rev. B84, 235126 (2011)

  18. [25]

    B. Q. Lv, N. Xu, H. M. Weng, J. Z. Ma, P. Richard, X. C. Huang, L. X. Zhao, G. F. Chen, C. E. Matt, F. Bisti, V. N. Strocov, J. Mesot, Z. Fang, X. Dai, T. Qian, M. Shi, and H. Ding, Observation of Weyl nodes in TaAs, Nature Physics11, 724–727 (2015)

  19. [26]

    S.-Y. Xu, C. Liu, S. K. Kushwaha, R. Sankar, J. W. Krizan, I. Belopolski, M. Neupane, G. Bian, N. Ali- doust, T.-R. Chang, H.-T. Jeng, C.-Y. Huang, W.-F. Tsai, H. Lin, P. P. Shibayev, F.-C. Chou, R. J. Cava, and M. Z. Hasan, Observation of Fermi arc surface states in a topolog...

  20. [27]

    Huang, L

    X. Huang, L. Zhao, Y. Long, P. Wang, D. Chen, Z. Yang, H. Liang, M. Xue, H. Weng, Z. Fang, X. Dai, and G. Chen, Observation of the Chiral-Anomaly-Induced Negative Magnetoresistance in 3D Weyl Semimetal TaAs, Phys. Rev. X5, 031023 (2015)

  21. [28]

    Q. Xu, E. Liu, W. Shi, L. Muechler, J. Gayles, C. Felser, and Y. Sun, Topological surface Fermi arcs in the mag- netic Weyl semimetal Co3Sn2S2, Phys. Rev. B97, 235416 (2018)

  22. [29]

    Y. Xu, J. Zhao, C. Yi, Q. Wang, Q. Yin, Y. Wang, X. Hu, L. Wang, E. Liu, G. Xu, L. Lu, A. Soluyanov, H. Lei, Y. Shi, J. Luo, and Z.-G. Chen, Electronic corre- lations and flattened band in magnetic Weyl semimetal candidate Co 3Sn2S2, Nature Communications11, 3985 (2020)

  23. [30]

    R. Zu, M. Gu, L. Min, C. Hu, N. Ni, Z. Mao, J. M. Rondinelli, and V. Gopalan, Comprehensive anisotropic linear optical properties of the Weyl semimetals TaAs and NbAs, Phys. Rev. B103, 165137 (2021)

  24. [31]

    Bonasera, S.-B

    F. Bonasera, S.-B. Zhang, L. Privitera, and F. M. D. Pel- legrino, Tunable interface states between Floquet-Weyl semimetals, Phys. Rev. B106, 195115 (2022)

  25. [32]

    Wilczek, Two applications of axion electrodynamics, Phys

    F. Wilczek, Two applications of axion electrodynamics, Phys. Rev. Lett.58, 1799–1802 (1987)

  26. [33]

    A. A. Zyuzin and A. A. Burkov, Topological response in Weyl semimetals and the chiral anomaly, Phys. Rev. B 86, 115133 (2012)

  27. [34]

    M. M. Vazifeh and M. Franz, Electromagnetic Response of Weyl Semimetals, Phys. Rev. Lett.111, 027201 (2013)

  28. [35]

    Goswami and S

    P. Goswami and S. Tewari, Axionic field theory of (3+1)- dimensional Weyl semimetals, Phys. Rev. B88, 245107 (2013)

  29. [36]

    A. A. Zyuzin and V. A. Zyuzin, Chiral electromagnetic waves in Weyl semimetals, Phys. Rev. B92, 115310 (2015)

  30. [37]

    O. V. Kotov and Y. E. Lozovik, Giant tunable nonre- ciprocity of light in Weyl semimetals, Phys. Rev. B98, 195446 (2018)

  31. [38]

    Sekine and K

    A. Sekine and K. Nomura, Axion electrodynamics in topological materials, Journal of Applied Physics129, 141101 (2021)

  32. [39]

    X.-L. Qi, R. Li, J. Zang, and S.-C. Zhang, Inducing a Magnetic Monopole with Topological Surface States, Sci- ence323, 1184–1187 (2009)

  33. [40]

    Tse and A

    W.-K. Tse and A. H. MacDonald, Giant Magneto- Optical Kerr Effect and Universal Faraday Effect in Thin-Film Topological Insulators, Phys. Rev. Lett.105, 057401 (2010)

  34. [41]

    A. G. Grushin and A. Cortijo, Tunable Casimir Re- pulsion with Three-Dimensional Topological Insulators, Phys. Rev. Lett.106, 020403 (2011)

  35. [42]

    Rodriguez-Lopez, Casimir repulsion between topolog- 13 ical insulators in the diluted regime, Phys

    P. Rodriguez-Lopez, Casimir repulsion between topolog- 13 ical insulators in the diluted regime, Phys. Rev. B84, 165409 (2011)

  36. [43]

    Chang and M.-F

    M.-C. Chang and M.-F. Yang, Optical signature of topo- logical insulators, Phys. Rev. B80, 113304 (2009)

  37. [44]

    J. A. Crosse, S. Fuchs, and S. Y. Buhmann, Electromag- netic Green’s function for layered topological insulators, Phys. Rev. A92, 063831 (2015)

  38. [45]

    O. J. Franca and S. Y. Buhmann, Modification of tran- sition radiation by three-dimensional topological insula- tors, Phys. Rev. B105, 155120 (2022)

  39. [46]

    F. M. D. Pellegrino, M. I. Katsnelson, and M. Polini, Helicons in Weyl semimetals, Phys. Rev. B92, 201407(R) (2015)

  40. [47]

    Zhou, H.-R

    J. Zhou, H.-R. Chang, and D. Xiao, Plasmon mode as a detection of the chiral anomaly in Weyl semimetals, Phys. Rev. B91, 035114 (2015)

  41. [48]

    J. C. W. Song and M. S. Rudner, Fermi arc plasmons in Weyl semimetals, Phys. Rev. B96, 205443 (2017)

  42. [49]

    G. M. Andolina, F. M. D. Pellegrino, F. H. L. Koppens, and M. Polini, Quantum nonlocal theory of topological Fermi arc plasmons in Weyl semimetals, Phys. Rev. B 97, 125431 (2018)

  43. [50]

    Tamaya, T

    T. Tamaya, T. Kato, K. Tsuchikawa, S. Konabe, and S. Kawabata, Surface plasmon polaritons in thin-film Weyl semimetals, Journal of Physics: Condensed Mat- ter31, 305001 (2019)

  44. [51]

    Tsuchikawa, S

    K. Tsuchikawa, S. Konabe, T. Yamamoto, and S. Kawa- bata, Characterization of a Weyl semimetal using a unique feature of surface plasmon polaritons, Phys. Rev. B102, 035443 (2020)

  45. [52]

    O. V. Bugaiko, E. V. Gorbar, and P. O. Sukhachov, Surface plasmon polaritons in strained Weyl semimetals, Phys. Rev. B102, 085426 (2020)

  46. [53]

    Heidari, D

    S. Heidari, D. Culcer, and R. Asgari, Anomalous plasmon mode in strained Weyl semimetals, Phys. Rev. B103, 035306 (2021)

  47. [54]

    Peluso, A

    M. Peluso, A. De Martino, R. Egger, and F. Buccheri, Nonreciprocal Weyl semimetal waveguide, Phys. Rev. Res.7, 023195 (2025)

  48. [55]

    F. M. D. Pellegrino, F. Buccheri, and G. G. N. Angilella, Localized surface plasmons in a Weyl semimetal nanosphere, Phys. Rev. B112, 075431 (2025)

  49. [57]

    Zhang, C.-X

    H. Zhang, C.-X. Liu, X.-L. Qi, X. Dai, Z. Fang, and S.- C. Zhang, Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface, Nature Physics5, 438–442 (2009)

  50. [58]

    L. Wu, M. Salehi, N. Koirala, J. Moon, S. Oh, and N. P. Armitage, Quantized Faraday and Kerr rotation and ax- ion electrodynamics of a 3D topological insulator, Science 354, 1124–1127 (2016)

  51. [59]

    Dziom, A

    V. Dziom, A. Shuvaev, A. Pimenov, G. V. As- takhov, C. Ames, K. Bendias, J. B¨ ottcher, G. Tkachov, E. M. Hankiewicz, C. Br¨ une, H. Buhmann, and L. W. Molenkamp, Observation of the universal magnetoelec- tric effect in a 3D topological insulator, Nature Commu- nications8, 151...

  52. [60]

    L.-L. Wang, N. H. Jo, B. Kuthanazhi, Y. Wu, R. J. Mc- Queeney, A. Kaminski, and P. C. Canfield, Single pair of Weyl fermions in the half-metallic semimetal EuCd 2As2, Phys. Rev. B99, 245147 (2019)

  53. [61]

    H. P. Wang, D. S. Wu, Y. G. Shi, and N. L. Wang, Anisotropic transport and optical spectroscopy study on antiferromagnetic triangular lattice EuCd2As2: An inter- play between magnetism and charge transport properties, Phys. Rev. B94, 045112 (2016)

  54. [62]

    Krishna, T

    J. Krishna, T. Nautiyal, and T. Maitra, First-principles study of electronic structure, transport, and optical prop- erties of EuCd 2As2, Phys. Rev. B98, 125110 (2018)

  55. [63]

    G. Xu, H. Weng, Z. Wang, X. Dai, and Z. Fang, Chern Semimetal and the Quantized Anomalous Hall Effect in HgCr2Se4, Phys. Rev. Lett.107, 186806 (2011)

  56. [64]

    J. Li, Y. Li, S. Du, Z. Wang, B.-L. Gu, S.-C. Zhang, K. He, W. Duan, and Y. Xu, Intrinsic magnetic topolog- ical insulators in van der Waals layered MnBi2Te4 family materials, Science Advances5, eaaw5685 (2019)

  57. [65]

    Y. Gao, W. Wu, B.-C. Gong, H.-C. Yang, X.-F. Zhou, Y. Liu, S. A. Yang, K. Liu, and Z.-Y. Lu, Intrinsic fer- romagnetic axion states and single pair of Weyl fermions in the stable-state MnX 2B2T6 family of materials, Phys. Rev. B107, 045136 (2023)

  58. [66]

    J. A. Boulton and K. W. Kim, Search for an an- tiferromagnetic Weyl semimetal in (MnTe) m(Sb2Te3)n and (MnTe)m(Bi2Te3)n superlattices, Journal of Physics: Condensed Matter36, 405601 (2024)

  59. [67]

    H. Liu, J. Cao, Z. Zhang, J. Liang, L. Wang, and S. A. Yang, Ideal spin-polarized Weyl half-semimetal with a single pair of Weyl points in the half-Heusler compounds XCrTe (X= K, Rb), Phys. Rev. B109, 174426 (2024)

  60. [68]

    A. B. Sushkov, J. B. Hofmann, G. S. Jenkins, J. Ishikawa, S. Nakatsuji, S. Das Sarma, and H. D. Drew, Optical evi- dence for a Weyl semimetal state in pyrochlore Eu2Ir2O7, Phys. Rev. B92, 241108(R) (2015)

  61. [69]

    L. Y. Cao, Z. A. Xu, B. X. Gao, L. Wang, X. T. Zhang, X. Y. Zhang, Y. F. Guo, and R. Y. Chen, Optical study of the three-dimensional Weyl semimetal Mn 3Sn, Phys. Rev. B108, 235109 (2023)

  62. [70]

    Lohani, P

    H. Lohani, P. Foulquier, P. Le F` evre, F. Bertran, D. Col- son, A. Forget, and V. Brouet, Electronic structure evolu- tion of the magnetic Weyl semimetal Co3Sn2S2 with hole and electron doping, Phys. Rev. B107, 245119 (2023)

  63. [71]

    I. S. Gradshteyn and I. M. Ryzhik,Table of integrals, series, and products, 7th ed. (Elsevier/Academic Press, Amsterdam, 2007)

  64. [72]

    Mart ´ ın-Ruiz, M

    A. Mart ´ ın-Ruiz, M. Cambiaso, and L. F. Urrutia, Elec- tromagnetic fields induced by an electric charge near a Weyl semimetal, Phys. Rev. B99, 155142 (2019)

  65. [73]

    Lindell, Quasi-static image theory for the bi-isotropic sphere, IEEE Transactions on Antennas and Propagation 40, 228–233 (1992)

    I. Lindell, Quasi-static image theory for the bi-isotropic sphere, IEEE Transactions on Antennas and Propagation 40, 228–233 (1992)

  66. [74]

    Brevik, Experiments in phenomenological electrody- namics and the electromagnetic energy-momentum ten- sor, Physics Reports52, 133–201 (1979)

    I. Brevik, Experiments in phenomenological electrody- namics and the electromagnetic energy-momentum ten- sor, Physics Reports52, 133–201 (1979)

  67. [75]

    S. M. Barnett and R. Loudon, The enigma of optical mo- mentum in a medium, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineer- ing Sciences368, 927–939 (2010)

  68. [76]

    Goldstein, C

    H. Goldstein, C. Poole, and J. Safko,Classical Mechan- ics, 3rd ed. (Addison-Wesley, 2001)

  69. [77]

    A. J. Fleming, A review of nanometer resolution posi- tion sensors: Operation and performance, Sensors and Actuators A: Physical190, 106–126 (2013)

  70. [78]

    Chighizola, L

    M. Chighizola, L. Puricelli, L. Bellon, and A. Podest` a, Large colloidal probes for atomic force microscopy: Fab- rication and calibration issues, Journal of Molecular Recognition34, e2879 (2021). 14

  71. [79]

    Voigtl¨ ander, V

    B. Voigtl¨ ander, V. Cherepanov, S. Korte, A. Leis, D. Cuma, S. Just, and F. L¨ upke, Invited Review Article: Multi-tip scanning tunneling microscopy: Experimental techniques and data analysis, Review of Scientific Instru- ments89, 101101 (2018)

  72. [80]

    T. M. Hoang, Y. Ma, J. Ahn, J. Bang, F. Robicheaux, Z.-Q. Yin, and T. Li, Torsional Optomechanics of a Lev- itated Nonspherical Nanoparticle, Phys. Rev. Lett.117, 123604 (2016)

  73. [81]

    Reimann, M

    R. Reimann, M. Doderer, E. Hebestreit, R. Diehl, M. Frimmer, D. Windey, F. Tebbenjohanns, and L. Novotny, GHz Rotation of an Optically Trapped Nanoparticle in Vacuum, Phys. Rev. Lett.121, 033602 (2018)

  74. [82]

    J. Ahn, Z. Xu, J. Bang, P. Ju, X. Gao, and T. Li, Ul- trasensitive torque detection with an optically levitated nanorotor, Nature Nanotechnology15, 89–93 (2020)

Pith tools

Reviewed July 30, 2026 · model on record in the stance chip above.