Dirac and Weyl Semimetal in XYBi (X = Ba, Eu; Y = Cu, Ag and Au)
نویسندگان
چکیده
Weyl and Dirac semimetals recently stimulate intense research activities due to their novel properties. Combining first-principles calculations and effective model analysis, we predict that nonmagnetic compounds BaYBi (Y = Au, Ag and Cu) are Dirac semimetals. As for the magnetic compound EuYBi, although the time reversal symmetry is broken, their long-range magnetic ordering cannot split the Dirac point into pairs of Weyl points. However, we propose that partially substitute Eu ions by Ba ions will realize the Weyl semimetal.
منابع مشابه
Phenomenology of a semi-Dirac semi-Weyl semimetal
We extend the semiclassical study of fermionic particle-hole symmetric semi-Dirac (more appropriately, semiDirac semi-Weyl) dispersion of quasiparticles, εK = ± √ (k2 x/2m) + (vky)) = ±ε0 √ K4 x +K2 y in dimensionless units, discovered computationally in oxide heterostructures by Pardo and collaborators. This unique system is a highly anisotropic sister phase of both (symmetric) graphene and wh...
متن کاملThe Exploration Significance of Ag/Au, Au/Cu, Cu/Mo, (Ag×Au)/(Cu×Mo) Ratios, Supra-ore and Sub-ore Halos and Fluid Inclusions in Porphyry Deposits: A Review
This paper documents the exploration significance of Ag/Au, Au/Cu, Cu/Mo and (Ag×Au)/Cu×Mo) ratios of the supra-ore and sub-ore halos versus fluid inclusion evolution for 24 Cu, 6 Cu- Mo and 10 Cu-Au porphyry deposits worldwide. The ratios are based only on the economic and mineralized hypogene alteration zones. The results indicate that (Ag×Au)/(Cu×Mo), Au/Cu and Cu/Mo ratios increase with dec...
متن کاملمقایسه کانسارCu-Ag-Au قلعه زری با دیگر کانسارهای نوع Iron Oxides Cu-Au (IOCG) و ارائه ردهبندی جدید
The Qaleh-Zari specularite- rich Cu-Au-Ag deposit is located 180 Km south of Birjand. Host rocks are mainly Tertiary andesites and andesitic basalts and some Jurassic shales and sandstones. Andesitic rocks from the western region of Qaleh-Zari were dated to 40.5±2 Ma. Four trends of faults and joints are identified in the mine area. The oldest is mineralized. Three major sub-parallel quartz ve...
متن کاملSpectroscopy of image-potential states with inverse photoemission.
Cu(100), Cu(110), Ag(111},Au(111), and Au(100}), a semimetal [Sb(100}],and a layered compound {1T-TiS2). Data for Au{111) show that image-potential states exist even in the presence of bulk states. The coupling with bulk states is weak as indicated by the narrow {&0.1 eV) width of the image states. The binding energies of the lowest state cluster around 0.7 eV for a variety of metal and semimet...
متن کاملSpectroscopic evidence for a type II Weyl semimetallic state in MoTe2.
In a type I Dirac or Weyl semimetal, the low-energy states are squeezed to a single point in momentum space when the chemical potential μ is tuned precisely to the Dirac/Weyl point. Recently, a type II Weyl semimetal was predicted to exist, where the Weyl states connect hole and electron bands, separated by an indirect gap. This leads to unusual energy states, where hole and electron pockets to...
متن کامل