Abstract

We present a theoretical investigation of non-equilibrium thermal dynamics in graphene under femtosecond laser excitation, emphasizing the role of phonon-branch-resolved electron–phonon coupling. This framework provides new insight into ultrafast energy transfer processes at femtosecond timescales and illustrates key deviations from the predictions of the classical two-temperature model, particularly in spatially localized heat transport. Our results show that a 190 fs laser pulse induces a strong non-equilibrium state, followed by momentum redistribution among the excited carriers. This is then followed by effective cooling of the carrier distribution on a 450 fs timescale through phonon emission.

Abstract

We present a theoretical investigation of non-equilibrium thermal dynamics in graphene under femtosecond laser excitation, emphasizing the role of phonon-branch-resolved electron–phonon coupling. This framework provides new insight into ultrafast energy transfer processes at femtosecond timescales and illustrates key deviations from the predictions of the classical two-temperature model, particularly in spatially localized heat transport. Our results show that a 190 fs laser pulse induces a strong non-equilibrium state, followed by momentum redistribution among the excited carriers. This is then followed by effective cooling of the carrier distribution on a 450 fs timescale through phonon emission.

Abstract

We present a theoretical investigation of non-equilibrium thermal dynamics in graphene under femtosecond laser excitation, emphasizing the role of phonon-branch-resolved electron–phonon coupling. This framework provides new insight into ultrafast energy transfer processes at femtosecond timescales and illustrates key deviations from the predictions of the classical two-temperature model, particularly in spatially localized heat transport. Our results show that a 190 fs laser pulse induces a strong non-equilibrium state, followed by momentum redistribution among the excited carriers. This is then followed by effective cooling of the carrier distribution on a 450 fs timescale through phonon emission.

Abstract

We present a theoretical investigation of non-equilibrium thermal dynamics in graphene under femtosecond laser excitation, emphasizing the role of phonon-branch-resolved electron–phonon coupling. This framework provides new insight into ultrafast energy transfer processes at femtosecond timescales and illustrates key deviations from the predictions of the classical two-temperature model, particularly in spatially localized heat transport. Our results show that a 190 fs laser pulse induces a strong non-equilibrium state, followed by momentum redistribution among the excited carriers. This is then followed by effective cooling of the carrier distribution on a 450 fs timescale through phonon emission.