Publications

Cavity electrodynamics of van der Waals heterostructures

G. Kipp, H. M. Bretscher, B. Schulte, D. Herrmann, K. Kusyak, M. W. Day, S. Kesavan, T. Matsuyama, X. Li, S. Langner, J. Hagelstein, F. Sturm, A. M. Potts, C. J. Eckhardt, Y. Huang, K. Watanabe, T. Taniguchi, A. Rubio, D. M. Kennes, M. A. Sentef, E. Baudin, G. Meier, M. H. Michael, J. W. McIver
https://arxiv.org/abs/2403.19745 (2024)
Our findings show that intrinsic cavity modes of metallic gates can sense and manipulate the low-energy electrodynamics of vdW heterostructures.

Electronic interactions in Dirac fluids visualized by nano-terahertz spacetime mapping

S. Xu, Y. Li, R. A. Vitalone, R. Jing, A. J. Sternbach, S. Zhang, J. Ingham, M. Delor, J. McIver, M. Yankowitz, R. Queiroz, A. J. Millis, M. M. Fogler, C. R. Dean, J. Hone, M. Liu, DN Basov
https://arxiv.org/abs/2311.11502 (2023)
Our imaging methodology can be used to probe the electromagnetics of quantum materials other than graphene in order to provide fs-scale diagnostics under near-equilibrium conditions.

Direct Optical Probe of Magnon Topology in Two-Dimensional Quantum Magnets

E.V. Boström, T.S. Parvini, J.W. McIver, A. Rubio, S. Viola-Kusminskiy & M.A. Sentef
Physical Review Letters 130, 026701 (2023)
Here we derive a fundamental relation between the light-matter coupling and the quantum geometry of magnon states.

Colloquium: Nonthermal pathways to ultrafast control in quantum materials

A. de la Torre, D.M. Kennes, M. Claassen, S. Gerber, J.W. McIver & M.A. Sentef
Reviews of Modern Physic 93, 041002 (2021)
A review of recent progress in utilizing ultrafast light-matter interaction to control the properties of quantum materials.

All-optical generation of antiferromagnetic magnon currents via the magnon circular photogalvanic effect

E.V. Boström, T.S. Parvini, J.W. McIver, A. Rubio, S. Viola-Kusminskiy & M.A. Sentef
Physical Review B 104, L100404 (2021)
Circularly polarized light is predicted to induce magnon photocurrents in honeycomb antiferromagnetic insulators via two-magnon Raman scattering.

The 2021 quantum materials roadmap

F. Giustino, J.H. Lee, F. Trier, M. Bibes, S.M. Winter, R. Valenti, Y.W. Son, L. Taillefer, C. Heil, A.I. Figueroa, B. Plaçais, Q.S. Wu, O.V. Yazyev, E.P.A.M. Bakkers, J. Nygård, P. Forn-Díaz, S. De Franceschi, J.W. McIver, L.E.F. Foa Torres, T. Low, A. Kumar, R. Galceran, S.O. Valenzuela, M.V. Costache, A. Manchon, E.A. Kim, G.R. Schleder, A. Fazzio & S. Roche
Journal of Physics: Materials 3, 042006 (2021)
A roadmap of what lies ahead in quantum materials research with a section on non-equilibrium phenomena.

Light-induced topological magnons in two-dimensional van der Waals magnets

E.V. Boström, M. Claassen, J.W. McIver, G. Jotzu, A. Rubio & M.A. Sentef
SciPost Physics 9, 061 (2020)
Circularly polarized light is predicted to induce topological magnonic edge states in 2D van der Waals magnets.

40 years of the quantum Hall effect (viewpoint)

Klaus von Klitzing, Tapash Chakraborty, Philip Kim, Vidya Madhavan, Xi Dai, James McIver, Yoshinori Tokura, Lucile Savary, Daria Smirnova, Ana Maria Rey, Claudia Felser, Johannes Gooth & Xiaoliang Qi
Nature Reviews Physics 2, 397-401 (2020)
Reflections on how the discovery of the quantum Hall effect shaped 40 years of physics research, including topological Floquet engineering in solids.

Floquet dynamics in light-driven solids

M. Nuske, L. Broers, B. Schulte, G. Jotzu, S.A. Sato, A. Cavalleri, A. Rubio, J.W. McIver & L. Mathey
Physical Revew Research 2, 043408 (2020)
A theoretical investigation into how light-induced Floquet-Bloch states in solids impact natural physical observables, such as transport properties, by capturing the environmental influence on the electrons.

Light-induced anomalous Hall effect in graphene

J.W. McIver*, B. Schulte*, F.-U. Stein*, T. Matsuyama, G. Jotzu, G. Meier & A. Cavalleri
Nature Physics 16, 38-41 (2020) (cover story)
  - Editorial in Nature Physics  
  - News & Views by J.C.W. Song
  - MPSD press release
Ultrafast transport measurements reveal an anomalous Hall effect in graphene driven by circularly polarized light. A Floquet-engineered topological band structure is the source of the effect.

Topological Floquet engineering of twisted bilayer graphene

G.E. Topp, G. Jotzu, J.W. McIver, L. Xian, A. Rubio & M.A. Sentef
Physical Review Research 1, 023031 (2019)
Twisted bilayer graphene is predicted to host topological phases when dressed by light. The topological phase diagram can be explored using an applied DC displacement field.

Microscopic theory for the light-induced anomalous Hall effect in graphene

S.A. Sato, J.W. McIver, M. Nuske, P. Tang, G. Jotzu, B. Schulte, H. Hübener, U. De Giovannini, L. Mathey, M.A. Sentef, A. Cavalleri & A. Rubio
Physical Review B 99, 214302 (2019)
Numerical simulations on optically-driven graphene reveal that a DC bias field coherently modifies how topological Floquet-Bloch states are populated.

Valley-selective optical Stark effect in monolayer WS₂

E.J. Sie, J.W. McIver, Y.H. Lee, L. Fu, J. Kong & N. Gedik
Nature Materials 14, 290-294 (2015) (cover story)
Pulsed laser light induces an AC Stark shift of the exciton levels in monolayer WS₂. The effect can be used to break the valley-degeneracy when using circularly polarized light.

Control over topological insulator photocurrents with light polarization

J.W. McIver*, D. Hsieh*, H. Steinberg, P. Jarillo-Herrero & N. Gedik
Nature Nanotechnology 7, 96-100 (2012)
   - News & Views by Judy J. Cha & Yi Cui
   - Research Highlight in Nature Photonics
Laser light induces a photocurrent in Bi₂Se₃ that originates from the topological surface states. The direction of the current flow can be controlled by changing the light polarization.

Theoretical and experimental study of second harmonic generation from the surface of the topological insulator Bi₂Se₃

J.W. McIver, D. Hsieh, S.G. Drapcho, D.H. Torchinsky, D.R. Gardner, Y.S. Lee & N. Gedik
Physical Review B 86, 035327 (2012)
A detailed look into how different gas environments affect surface second harmonic generation in the topological insulator Bi₂Se₃, and how these effects can be modelled theoretically.

Selective probing of photoinduced charge and spin dynamics in the bulk and surface of a topological insulator

D. Hsieh, F. Mahmood, J.W. McIver, D. R. Gardner, Y. S. Lee & N. Gedik
Physical Review Letters 107, 077401 (2011)
Time-resolved second harmonic generation measurements reveal the relaxation pathways of photo-excited charge and spin on the surface of Bi₂Se₃.

Nonlinear optical probe of tunable surface electrons on a topological insulator

D. Hsieh*, J.W. McIver*, D. H. Torchinsky, D. R. Gardner, Y. S. Lee & N. Gedik
Physical Review Letters 106, 057401 (2011)
Second harmonic generation is found to be a sensitive probe of the surface electronic response of the topological insulator Bi₂Se₃.

Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole and electron doped BaFe₂As₂

D.H. Torchinsky, J.W. McIver, D. Hsieh, G.F. Chen, J.L. Luo, N. L. Wang & N. Gedik
Physical Review B 84, 104518 (2011)
Time-resolved reflectivity measurements in iron pnictide superconductors identify two distinct relaxation pathways for excited quasiparticles. The results constrain the possible superconducting gap symmetries.

Band-dependent quasiparticle dynamics in the hole-doped Ba-122 iron pnictides

D.H. Torchinsky, J.W. McIver, D. Hsieh, G.F. Chen, J.L. Luo, N.L. Wang & N. Gedik
Journal of Physics and Chemistry of Solids 72, 519-522 (2011)
Ultrafast pump-probe spectroscopy on Ba-122 pnictides shows that both inter- and intraband scattering processes contribute to the non-equilibrium quasiparticle dynamics.

Applications of ³He spin filters at the NCNR

W.C. Chen, R. Erwin, J.W. McIver, S. Watson, C.B. Fu, T.R. Gentile, J.A. Borchers, J.W. Lynn & G.L. Jones
Physica B 404, 2663 (2009)
An overview of how ³He spin filters can be used to spin-polarize neutron beams for magnetic neutron scattering experiments.

End-compensated magneto-static cavity for polarized ³He neutron spin filters

J.W. McIver, R. Erwin, W.C. Chen, and T.R. Gentile
Rev. Sci. Instr. 80, 063905 (2009)
An improved cavity design for maintaining ³He neutron spin filter polarization.

Wrinkling of a bilayer membrane

A. Concha, J.W. McIver, P. Mellado, D. Clarke, O. Tchernyshyov, and R. L. Leheny
Phys. Rev. E 75, 016609 (2007)
Wrinkling formation is investigated in a soft-matter bilayer membrane from an experimental and analytical perspective.