Fig. 2

Optically induced nonthermal Weyl semimetal. a Self-consistent TDDFT + U calculation of U_eff(t) (Ir 5d) for Y₂Ir₂O₇ under pump excitation (0.41 eV frequency, 25.4 fs duration). U_eff decreases, initially following the pulse envelope. After 20 fs it reaches a plateau, which decreases for higher intensities. Relative changes of U_eff are 1.2% (blue), 5.3% (green), 9.6% (red) and 40.4% (cyan). b Time-dependent AIAO magnetisation from TDDFT + U. For the smallest intensity (blue) the magnetisation drops by 25%. For all higher pump intensities, there is a massive decrease of the magnetisation by 88% (red) and 92% (green, brown), respectively. c Time-dependent AIAO magnetisation m(t) (model) for bath coupling Γ₀ = 0.008 eV after instantaneous quenches at t = 0 from U_i = 1.28 eV to U_q = 1.24, 1.20 and 1.16 eV, respectively (dashed curves are without bath, Γ₀ = 0). Thermal m values for U_q are indicated by coloured arrows for reference. After a fast drop followed by an over-damped oscillation, the magnetisation slowly converges towards the respective thermal value. d Equilibrium phase diagram as a function of T and U with optically induced nonthermal states. Effective temperatures T_eff (see Supplementary Fig. 3) of the nonequilibrium states at t_p = 123.4 fs after the quench from the initial thermal state (red square), for quench values U_q as indicated (see Supplementary Fig. 2). Pentagons (squares) indicate nonequilibrium WSM states for the open system (closed system). (see Fig. 3). The black diamond indicates a nonequilibrium AFI state