The power of flexible lattice in Ca3Ru2O7: Exquisite control of the electrical transport via anisotropic magnetostriction

TL;DR

This study demonstrates how the flexible lattice in Ca3Ru2O7 allows precise control of electronic transport properties through anisotropic magnetostriction, revealing a unique lattice-dependent magnetotransport mechanism.

Contribution

It uncovers the role of anisotropic magnetostriction in controlling electronic states and transport in Ca3Ru2O7, highlighting the interplay between lattice flexibility and magnetic field orientation.

Findings

Magnetic field induces uniaxial lattice strain affecting electronic states.

Pressure enhances magnetoelastic effects, altering metallic and nonmetallic states.

Lattice flexibility enables control of electronic phases via magnetic and pressure tuning.

Abstract

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.