Fig. 4: Analysis of the temperature-dependent reflectivity transients (ΔR/R) after 3.1 eV photoexcitation.
From: Ultrafast signatures of spin and orbital order in antiferromagnetic α-Sr2CrO4

a ΔR/R at time delays of 0.2 ps (black circles), 4 ps (red squares), and 100 ps (blue diamonds). We also plot the amplitude B1 (orange circles) obtained from our curve fits. b Transient reflectivity data at temperature T = 20 K (blue circles) and 180 K (red circles), along with fits using the model described in the text. The data and fit curve at 180 K are scaled up by a factor of four for clear comparison. c The rise time (τ3) and (d) decay time (τ4) obtained from the ultrafast dynamics in (b), revealing a clear anomaly across the antiferro-type orbital ordering temperature TO = 140 K. The error bars were calculated as described in Methods.