Fermi surface topology of Ca1.5Sr0.5RuO4 determined by angle-resolved photoelectron spectroscopy.
We report angle-resolved photoelectron spectroscopy results of the Fermi surface of Ca1.5Sr0.5RuO4, which is at the boundary of magnetic/orbital instability in the phase diagram of the Ca-substituted Sr ruthenates. Three t(2g) energy bands and the corresponding Fermi surface sheets are observed, which are also present in the Ca-free Sr2RuO4. We find that while the Fermi surface topology of the alpha,beta (d(yz,zx)) sheets remains almost the same in these two materials, the gamma (d(xy)) sheet exhibits a holelike Fermi surface in Ca1.5Sr0.5RuO4 in contrast to being electronlike in Sr2RuO4. Our observation of all three volume conserving Fermi surface sheets clearly demonstrates the absence of orbital-selective Mott transition, which was proposed theoretically to explain the unusual transport and magnetic properties in Ca1.5Sr0.5RuO4.
Wang
S-C
SC
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Yang
H-B
HB
Sekharan
A K P
AK
Souma
S
S
Matsui
H
H
Sato
T
T
Takahashi
T
T
Lu
Chenxi
C
Zhang
Jiandi
J
Jin
R
R
Mandrus
D
D
Plummer
E W
EW
Wang
Z
Z
Ding
H
H