Coherent and incoherent $d$ band dispersions in ${\text{SrVO}}_3$

We have performed an angle-resolved photoemission spectroscopy study of ${\text{SrVO}}_3$ thin films. Utilizing thin films prepared in situ, with well-defined and atomically flat surfaces, contributions from surface states centered at $\sim -1.5\text{eV}$ were dramatically reduced, enabling us to study the bulklike $\text{V}3d$ states, including the incoherent part. A clear band dispersion is observed not only in the coherent part but also in the incoherent part and the spectral weight of the incoherent part is larger within the Fermi volume. These findings are particularly significant since the description of the so-called incoherent Hubbard band in ${\text{SrVO}}_3$ needs to include the nonlocal interaction between the atoms. These trends are well reproduced by dynamical mean-field theory calculations.

Figure 1

(Color online) EDCs of ${\text{SrVO}}_3$ thin films. (a) Entire valence-band region. (b) Near the Fermi level. (c) Traces in $k$ space including the uncertainties in the $k_z$ direction. Schematic Fermi surfaces of ${\text{SrVO}}_3$ (junglegymlike mutually penetrating cylinders) are indicated by shaded area.

Figure 2

(Color online) Experimental band structure deduced from the second derivative of EDCs, with bright parts corresponding to energy bands. LDA calculations from Ref. 23 and the fitted TB bands are shown by solid curves in the momentum range from $k_x=-\pi /a$ to 0 and from $k_x=0$ to $3\pi /a$, respectively. As for the TB bands, the diffraction replicas due to the $\sqrt{2}\times \sqrt{2}$ surface superstructure are also shown by dashed curves.

Figure 3

(Color online) Energy-dependent and momentum-dependent spectral weight near the Fermi level (Ref. 25). (a) Experimental intensity plot for ${\text{SrVO}}_3$. Peak positions of the EDCs and MDCs are shown by filled circles and open squares, respectively. The $\text{V}3d$ bands from the LDA calculation and tight-binding calculation are also shown by solid thick and thin curves, respectively. Broken curves are LDA bands renormalized by a factor of 2. (b) Intensity plot of spectral function from DMFT calculation with $U/W_{occ}=1.5$, where $W_{occ}=0.4W$ is the width of the occupied part of the band.