  The detailed information of the electronic structure is the key for
understanding the nature of charge density wave (CDW) order and its
relationship with superconducting order in microscopic level. In this paper, we
present high resolution laser-based angle-resolved photoemission spectroscopy
(ARPES) study on the three-dimensional (3D) hole-like Fermi surface around the
Brillouin zone center in a prototypical qusi-one-dimensional CDW and
superconducting system ZrTe3. Double Fermi surface sheets are clearly resolved
for the 3D hole-like Fermi surface around the zone center. The 3D Fermi surface
shows a pronounced shrinking with increasing temperature. In particular, the
quasiparticle scattering rate along the 3D Fermi surface experiences an anomaly
near the charge density wave transition temperature of ZrTe3 (~63 K). Signature
of electron-phonon coupling is observed with a dispersion kink at ~20 meV; the
strength of the electron-phonon coupling around the 3D Fermi surface is rather
weak. These results indicate that the 3D Fermi surface is also closely
connected to the charge-density-wave transition and suggest a more global
impact on the entire electronic structure induced by CDW phase transition in
ZrTe3.
