Amplitude and interlayer phase structure of SDW-induced modulations

Determine the amplitude and interlayer phase structure of the charge and orbital modulations induced at twice the spin-density-wave wavevector in the SDW-ordered state of trilayer La₄Ni₃O₁₀.

Background

The paper explains that the primary bond-order instability produces an inner-layer-centered orbital response above the spin-density-wave transition. Below the transition, however, a second-order response to the SDW order parameter can generate additional charge and orbital modulations at 2Qₛdw, coinciding with the primary density-wave wavevector up to a sign and reciprocal-lattice vector.

The magnitude and interlayer phase relationship of these SDW-induced modulations could alter the layer distribution of the density modulation below the SDW transition. The paper does not calculate the ordered-state response and explicitly leaves this determination for future work.