Angle-resolved photoemission study of the quasi-one-dimensional superconductor β-Na0.33V2O5 -: art. no. 140506

We have studied the electronic structure of beta-Na0.33V2O5, which becomes a superconductor under pressure, by angle-resolved photoemission spectroscopy. Clear band dispersions are observed only along the chain direction, indicating the quasi-one-dimensional (1D) electronic structure. The spectra of the V 3d band are dominated by a Gaussian-like broad feature at similar to1 eV below the Fermi level (E-F) with negligible intensity at E-F, which we attribute to strong electron-phonon coupling as in other 1D polaronic metals. In the momentum space, the spectra show a maximum intensity at ksimilar to+/-pi/4b, where b is the V-V distance along the b axis, reflecting the band filling of the chain and/or ladder.