SRC Users' Meeting - Synchrotron Radiation Center - University of ...

Photoemission spectra, a.u.
-0.3
-0.2
0.5
0.6
K y = 0, K x / =
0.7
0.8
0.9
0.0
-0.1
Binding
Energy, eV
Figure 1: Momentum resolved photoemission data along k x of an optimally doped (x=0.15) LSCO
film under compressive strain. Note the band crossing the Fermi level for k x 0.8.
Figure 2: Dispersion of the 2-dimensional band for bulk LSCO (left), and for an in-plane
compressed film with identical doping (right). These figures were obtained by fitting experimental
data (similar to Fig 1) but along the two high-symmetry directions -X and -M (for the unstrained
sample, experimental data were taken from [Ino]). See also Fig 2 in reference attached [Abrecht].
Note the disappearance of the saddle point in the strained film, and the topological transition of
the Fermi Surface (zero energy cut) from so-called hole-like (unstrained) to electron-like (strained).
Critical temperature values were 38K (unstrained sample) and 44K (in-plane compressed sample).