Shubnikov-de Haas oscillations in Ca3Ru2O7 under pressure

The bilayer ruthenate Ca3Ru2O7 undergoes a series of phase transitions on cooling, which lead to a low carrier density state at low temperature. Hydrostatic pressure is applied on this material in order to track the Fermi surface whilst tuning and ultimately suppressing the high temperature phase transitions. Quantum oscillations in the Hall component of Ca3Ru2O7 are investigated as a function pressure using a piston-cylinder cell. As the pressure is increased, the oscillation frequency decreases systematically, suggesting that the Fermi pockets shrink. Owing to the size of the frequencies and to the non-linear background, the evolution of the effective masses cannot be determined accurately enough to extract a trend other than that they remain of the order of 0.6me. Further work at higher pressures is under way, using anvil cells, to track the evolution of the Fermi surface through the pressures where the magnetic and structural transitions eventually are suppressed.