http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nature and topology of the low-energy states inZrTe5
Moreschini, L.,Johannsen, J. C.,Berger, H.,Denlinger, J.,Jozwiack, C.,Rotenberg, E.,Kim, K. S.,Bostwick, A.,Grioni, M. American Physical Society 2016 Physical Review B Vol.94 No.8
<P>Long known for its peculiar resistivity, showing a thus far unexplained anomalous peak as a function of temperature, ZrTe5 has recently received rising attention in a somewhat different context. While both theoretical and experimental results seem to point to a nontrivial topology of the low-energy electronic states, there is no agreement on the nature of their topological character. Here, by an angle-resolved photoemission study of the evolution of the band structure with temperature and surface doping, we show that (i) the material presents a van Hove singularity close to the Fermi level, and (ii) no surface states exist at the (010) surface. These findings reconcile band structure measurements with transport results and establish the topology of this puzzling compound.</P>
A novel quasi-one-dimensional topological insulator in bismuth iodide β-Bi<sub>4</sub>I<sub>4</sub>
Autè,s, Gabriel,Isaeva, Anna,Moreschini, Luca,Johannsen, Jens C.,Pisoni, Andrea,Mori, Ryo,Zhang, Wentao,Filatova, Taisia G.,Kuznetsov, Alexey N.,Forró,, Lá,szló,Van den Broek, Nature Publishing Group, a division of Macmillan P 2016 NATURE MATERIALS Vol.15 No.2
Recent progress in the field of topological states of matter has largely been initiated by the discovery of bismuth and antimony chalcogenide bulk topological insulators (TIs; refs ,,,), followed by closely related ternary compounds and predictions of several weak TIs (refs ,,). However, both the conceptual richness of Z<SUB>2</SUB> classification of TIs as well as their structural and compositional diversity are far from being fully exploited. Here, a new Z<SUB>2</SUB> topological insulator is theoretically predicted and experimentally confirmed in the β-phase of quasi-one-dimensional bismuth iodide Bi<SUB>4</SUB>I<SUB>4</SUB>. The electronic structure of β-Bi<SUB>4</SUB>I<SUB>4</SUB>, characterized by Z<SUB>2</SUB> invariants (1;110), is in proximity of both the weak TI phase (0;001) and the trivial insulator phase (0;000). Our angle-resolved photoemission spectroscopy measurements performed on the (001) surface reveal a highly anisotropic band-crossing feature located at the point of the surface Brillouin zone and showing no dispersion with the photon energy, thus being fully consistent with the theoretical prediction.
Bulk and surface band structure of the new family of semiconductors BiTeX (X=I, Br, Cl)
Moreschini, L.,Autes, G.,Crepaldi, A.,Moser, S.,Johannsen, J.C.,Kim, K.S.,Berger, H.,Bugnon, Ph.,Magrez, A.,Denlinger, J.,Rotenberg, E.,Bostwick, A.,Yazyev, O.V.,Grioni, M. Elsevier Scientific Pub. Co 2015 Journal of electron spectroscopy and related pheno Vol.201 No.-
We present an overview of the new family of semiconductors BiTeX (X=I, Br, Cl) from the perspective of angle resolved photoemission spectroscopy. The strong band bending occurring at the surface potentially endows them with a large flexibility, as they are capable of hosting both hole and electron conduction, and can be modified by inclusion or adsorption of foreign atoms. In addition, their trigonal crystal structure lacks a center of symmetry and allows for both bulk and surface spin-split bands at the Fermi level. We elucidate analogies and differences among the three materials, also in the light of recent theoretical and experimental work.