  Ca3Ru2O7 is a correlated and spin-orbit-coupled system with an extraordinary
anisotropy. It is both interesting and unique largely because this material
exhibits conflicting phenomena that are often utterly inconsistent with
traditional precedents, particularly, the quantum oscillations in the
nonmetallic state and colossal magnetoresistivity achieved by avoiding a fully
spin-polarized state. This work focuses on the relationship between the lattice
and transport properties along each crystalline axis and reveals that
application of magnetic field, H, along different crystalline axes readily
stretches or shrinks the lattice in a uniaxial manner, resulting in distinct
electronic states. Furthermore, application of modest pressure drastically
amplifies the anisotropic magnetoelastic effect, leading to either an
occurrence of a robust metallic state at H || hard axis or a reentrance of the
nonmetallic state at H || easy axis. Ca3Ru2O7 presents a rare lattice-dependent
magnetotransport mechanism, in which the extraordinary lattice flexibility
enables an exquisite control of the electronic state via magnetically
stretching or shrinking the crystalline axes, and the spin polarization plays
an unconventional role unfavorable for maximizing conductivity. At the heart of
the intriguing physics is the anisotropic magnetostriction that leads to exotic
states.
