Fig. 1: Spin and orbital order in α-Sr2CrO4. | Communications Physics

Fig. 1: Spin and orbital order in α-Sr2CrO4.

From: Ultrafast signatures of spin and orbital order in antiferromagnetic α-Sr2CrO4

Fig. 1

a Schematic diagrams of the spin- and orbital-ordered ground state in α-Sr2CrO4, showing different types of antiferro-type spin ordering and dyz/dzx orbital ordering. We note that the four-lobed shapes of the d-orbitals are projected into the ab-plane. Arrows indicate possible 1 eV transitions from occupied (filled shapes) to unoccupied (dotted shapes) orbital states in a given ordered phase; transitions from Cr(1) to Cr(2) ions are shown for simplicity, but the reverse can also occur. b Energy (E) levels and orbital structures on neighboring sites with Cr(1) and Cr(2) ions at a temperature (T) below the Néel temperature (TN): TTN. The d-d transitions between dzx orbitals from Cr(1) to Cr(2) (or between dyz orbitals from Cr(2) to Cr(1)) correspond to hopping energies of 1.0 eV. 3.1 eV excitation drives a charge-transfer-type transition from O 2p to Cr eg orbitals. The relevant electronic structures are displayed along with photoexcitation at (c) 1.0 eV and (d) 3.1 eV. On-site transitions from O 2p to Cr eg states are possible at both Cr(1) and Cr(2) sites.

Back to article page