Topological kern in three-dimensional crystals

Intrinsic Bulk Topological Invariants in Three-Dimensional Chern Insulators: Chern Vectors, Torus Knots and Hopf Links

The paradigmatic example of a topological phase of matter, the two-dimensional Chern insulator1,2,3,4,5, is characterized by a topological invariant consisting of a single integer, the scalar Chern number. The three-dimensional quantum Hall effect, similar to that of the two-dimensional phase, is needed to extend the Chern insulator phase from two to three dimensions. Such Chern vectors for 3D Chern insulators have never been explored experimentally. We used 3D optical crystals to demonstrate the behavior of the kelvin genes and their surface states. We demonstrate Chern vector magnitudes of up to six, higher than all scalar Chern numbers previously realized in topological materials. The isofrequency contours formed by the topological surface states in the surface Brillouin zone form torus knots or links, whose characteristic integers are determined by the Chern vectors. We demonstrate a sample with surface states forming a (2, 2) torus link or Hopf link in the surface Brillouin zone, which is topologically distinct from the surface states of other 3D topological phases. These results establish the Chern vector as an intrinsic bulk topological invariant in 3D topological materials, with surface states possessing unique topological characteristics.

Park, J. M., Cao, Y., Watanabe, K., Taniguchi, T. & Jarillo-Herrero, P. Flavour Hund’s coupling, Chern gaps and charge diffusivity in moiré graphene. The nature 592, 43–48 will be published next year.

Bose-Einstein condensation of excitons in ferromagnetic Bi2Te3 nanostructures and a photoexcited topological insulator

Towards Bose-Einstein condensation of excitons. Nature 417, 47–52 (2002).

Zhu, X., Littlewood, P. B., Hybertsen, M. S. & Rice, T. M. Exciton condensate in semiconductor quantum well structures. Lett. 74, 1633–1636 was published in 1995.

SoBota, J. A. It is possible to obtain ultrafast optical waves in Bi2Te3. Phys. Rev. Lett. 108, 117403 (2012).

The paper was titled “B. C. et al.” Bi2Te3 and Mn-doped Bi2Te3 have ferromagnetic properties. B 89, comes out in 2014).

A report on Hajlaoui, M. et al. Transient dirac cone electron-hole asymmetry is caused by tuning a sch OTTY barrier in a photoexcited topological insulator. Nat. Commun. 5, 3003 (2014).

A summary of the work by Dong, S. and others. Measure key exciton properties: energy, dynamics and spatial distribution. Nat. Sci. 1, e10010 (2021).

Jozwiak, C. et al. A spin-resolved photoemission spectrometer combines time-of-flight and exchange-scattering polarimetry. Rev.Sci. Instrum 81, 053904 was published in 2010.


Quantum ESPRESSO: an open-source software project for quantum simulation of topological materials I. MoS2 and its k-resolved electronic structure

P., et al. are the authors. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. The Journal of Psy. It is a Condenser. Matter 21, 395502

Van Setten, M. J. The pseudodojo: training and grading a 85 element optimized norm-conserving pseudopotential table. The Comput. is Comput. It’s the science of Phys. Commun. 226 was published in January of 2018?

Mostofi, A. A. et al. Wannier90 is a tool for getting maximally-localised Wannier functions. It is Comput. The language of science. Commun. 185, 2309–2310 (2014).

Wanniertools is an open-sourced software package for novel topological materials. It’s Comput. Some of the parts of Phys. Commun. The book is 224, 405, and 423.

The electronic band structure of MoS2 was studied with a sulfur-vacancy-caused occupied defect state. Phys. Chem. Chem. Phys. 21, 15302–15309 (2019).

V. N. et al. k-resolved electronic structure of buried systems by soft-X-ray. J. Electron Spectros. Relat. Phenomena 236, 1–8 (2019).

Greenaway, D. L. & Harbeke, G. Band structure of bismuth telluride, bismuth selenide and their respective alloys. J. Physics Chem. Solids 26, 1585–1604 (1965).

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