Dynamics of Driven Dissipative Heisenberg Spins with Inertia

DSpace/Manakin Repository

Dynamics of Driven Dissipative Heisenberg Spins with Inertia

Show simple item record

dc.contributor.author Das, Jayajit
dc.date.accessioned 2009-08-25T10:30:07Z
dc.date.available 2009-08-25T10:30:07Z
dc.date.issued 2009-08-25T10:30:07Z
dc.date.submitted 2000
dc.identifier.uri http://hdl.handle.net/123456789/89
dc.description.abstract This thesis is a study of the interplay between inertia, dissipation and driving on the dynamics of many-body systems in d-dimensions. The simplest example of a many-body spin system possessing inertial dynamics is the Heisenberg Model in which the spins precess in response to the local magnetic field. It is convenient to work with coarse grained magnetisation variables, while focussing the study at length scales much larger than any microscopic length(Typically of order lattice). By using the Hubbard-Stratonovich transformation the coarse graining is realised in a systematic way, and then the Landau-Ginzburg free-energy functional is obtained by taking a continuum limit. As in the single particle example the study arrives at equations of motion for the spin starting with a Heisenberg spin model interacting with a heat bath(consists of phonons or electrons) the resulting equations of motion have both inertia and dissipation and also thermal noise. The interplay between the inertia and dissipation is analysed by studying the ordering dynamics of this spin model as it approaches equilibrium following a quench from the high temperature phase. The effect of external driving on a Heisenberg magnet is studied in the presence of both dissipation and inertia. The last problem discusses the Heisenberg spins driven by an external thermal current generated by sandwiching the spin system between two different heat sources. In the last two problems the spin system is driven far from its equilibrium configuration. en_US
dc.subject Dynamics en_US
dc.subject Heisenberg Magnets en_US
dc.title Dynamics of Driven Dissipative Heisenberg Spins with Inertia en_US
dc.type.degree Ph.D en_US
dc.type.institution University of Madras en_US
dc.description.advisor Murthy, M.V.N.
dc.description.pages vi; 140p. en_US
dc.type.mainsub Physics en_US

Files in this item

Files Size Format View
UNMTH64.pdf 10.15Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record

Search DSpace


Advanced Search

Browse

My Account