Heat exchanges in a quenched ferromagnet
Date of Issue2013
School of Physical and Mathematical Sciences
The off-equilibrium probability distribution of the heat exchanged by a ferromagnet in a time interval after a quench below the critical point is calculated analytically in the large-N limit. The distribution is characterized by a singular threshold Qc < 0, below which a macroscopic fraction of heat is released by the k = 0 Fourier component of the order parameter. The mathematical structure producing this phenomenon is the same responsible of the order parameter condensation in the equilibrium low temperature phase. The heat exchanged by the individual Fourier modes follows a non trivial pattern, with the unstable modes at small wave vectors warming up the modes around a characteristic finite wave vector kM. Two internal temperatures, associated to the k = 0 and k = kM modes, rule the heat currents through a fluctuation relation similar to the one for stationary systems in contact with two thermal reservoirs.
DRNTU::Science::Physics::Heat and thermodynamics
Journal of physics A : mathematical and theoretical
© 2013 IOP Publishing Ltd. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of physics A: mathematical and theoretical, IOP Publishing Ltd. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1088/1751-8113/46/4/042001].