Electronic correlations in vanadium chalcogenides: BaV Se₃versus BaV S₃

Abstract

Abstract. Albeit structurally and electronically very similar, at low temperature the quasi-one-dimensional vanadium sulfide BaVS 3 shows a metal-to-insulator transition via the appearance of a charge-density-wave state, while BaVSe 3 apparently remains metallic down to zero temperature. This different behavior upon cooling is studied by means of density functional theory and its combination with the dynamical meanfield theory and the rotationally-invariant slave-boson method. We reveal several subtle differences between these chalcogenides that provide indications for the deviant behavior of BaVSe 3 at low temperature. In this regard, a smaller Hubbard U in line with an increased relevance of the Hund's exchange J plays a vital role.

LDA + slave‐boson approach to the correlated electronic structure of the metamagnetic bilayer ruthenate Sr3Ru2O7

“…Yet optics experiments 26 point toward a similar U value. Here we scanned the onsite Coulomb interaction up to U = 3.45 eV, since it is also known that due to the neglect of quantum fluctuations in slave‐boson approaches, the effect of U may be underestimated 27.…”

Vanishing of the metal-insulator Peierls transition in pressurized BaVS3

“…25 BaVSe 3 exhibits a higher orthorhombic transition (T S ∼ 300 K 26 ) than BaVS 3 below P cr (T S < 270 K 15 ) and a stronger hybridization between dz 2 and e(t 2g ) orbitals. 24 In that case, we suspect that the possible 2k F dz 2 CDW instability cannot develop in BaVSe 3 due to the too short electronhole lifetime τ (i.e., stronger hybridization between dz 2 and e[(t 2g ]) orbitals).…”

Hidden spin-orbital hexagonal ordering induced by strong correlations in LiVS2

“…where N is the total charge operator, S the spin-, and L the angular momentum operators. We chose U = 3.5 eV and J H = 0.7 eV, appropriate for vanadium sulfides [18]. At DMFT self-consistency, the full multiorbital susceptibility tensor is also evaluated in a DMFT-like approximation, e.g., assuming the locality of the two-particle particle-hole irreducible vertex in the Bethe-Salpeter equation (BSE) in this channel (see Fig.…”

“…Within the LiVX 2 , X=(O,S,Se) series (see Appendix A and Refs. [8][9][10][11][12][13][14][15][16][17][18][19] for a qualitative phase diagram) the oxide is an insulator exhibiting an ordering transition at a critical temperature T c ∼ 500 K. The selenide has metallic character throughout the studied temperature regime. Upon cooling only the sulfide displays a metal-insulator transition (MIT) at T MIT ∼ 310 K from a paramagnetic metal to an insulating state with vanishing uniform * Alexander.Lichtenstein@physnet.uni-hamburg.de magnetic susceptibility [4,20].…”