Critical behavior within 20 fs drives the out-of-equilibrium laser-induced magnetic phase transition in nickel.

ABSTRACT: It has long been known that ferromagnets undergo a phase transition from ferromagnetic to paramagnetic at the Curie temperature, associated with critical phenomena such as a divergence in the heat capacity. A ferromagnet can also be transiently demagnetized by heating it with an ultrafast laser pulse. However, to date, the connection between out-of-equilibrium and equilibrium phase transitions, or how fast the out-of-equilibrium phase transitions can proceed, was not known. By combining time- and angle-resolved photoemission with time-resolved transverse magneto-optical Kerr spectroscopies, we show that the same critical behavior also governs the ultrafast magnetic phase transition in nickel. This is evidenced by several observations. First, we observe a divergence of the transient heat ca

SUBMITTER: Tengdin P 

PROVIDER: S-EPMC5834307 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature