Fig. 4.
Ultrafast radiative heat transfer induced by optical pumping. a Normalized absorption cross-sections σ abs of two graphene nanodisks (20 nm diameter, d = 1 nm separation) at the same initial temperature of 300 K but doped with different Fermi energies (see inset). b Time evolution of the electron temperatures T 1 and T 2 (left vertical scale, solid curves) and transferred energy fraction (right vertical scale, dashed curve) after optical pumping (150 mJ m−2 light fluence, 0.17 eV photon energy, as indicated by the red arrow of a)