Fig. 1: Dynamic axion field induced by antiferromagnetic resonance in DAI.
From: Doubled Shapiro steps in a dynamic axion insulator Josephson junction
a Schematic for a dynamic axion insulator driven by a linearly polarized coherent light. The arrows labeled B and E represent the magnetic and electric components of the applied light. The red and blue arrows labeled m1 and m2 represent the antiparallel magnetic moments forming a Néel vector, which oscillates linearly under the driving of the B component of the light. b and c are temporal evolutions of nx and nz under linearly polarized AFMR for three different amplitudes Ax = 0.1, 0.05, 0.02. The black stars mark five representative times ranging from t1 to t5. d Schematics for five representative magnetic configurations during a full circle one by one corresponding to the five times marked by black stars in b and c. The colorful arrows represent the magnetic moments m1 (m2) and θ1 (θ2) denotes their polar angles. The black arrow denotes the direction of motion of the magnetic moment. The tilting angles of the Néel vector are exaggerated for clarity. e Temporal dependence of the dynamic axion field δθ(t) obtained from Eq. (2) in the adiabatic limit at corresponding AFMR amplitudes.
