Fig. 1: Raman spectra coupled to the ground states of Ca₃Ru₂O₇.

a Crystal structure of Ca₃Ru₂O₇ with illustrated magnetic space group, symmetry operations and magnetic spins in the AFM-a and AFM-b phases. b Electronic and magnetic phase diagram of Ca₃Ru₂O₇. c Schematically depicted Raman lab geometry with respect to the crystal lattice of Ca₃Ru₂O₇. The \({E}_{i,s}\) and \({k}_{{is}}\) are polarization and wavevector or incident and scattered light respectively. d Representative polarized Raman intensities for Ca₃Ru₂O₇ at AFM-b and AFM-a phases respectively.