Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Tiefe Temperaturen
TT 29: Quantenkoh
ärenz und Quanteninformationssysteme II
TT 29.13: Vortrag
Donnerstag, 11. März 2004, 17:45–18:00, H19
Quantum versus classical temperature profiles — •Michael Hartmann1,2, Günter Mahler2 und Ortwin Hess3 — 1Institut für Technische Physik, DLR Stuttgart, Pfaffenwaldring 38 - 40, D-70569 Stuttgart — 2Institut für Theoretische Physik I, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart — 3School of Electronics & Physical Sciences, University of Surrey, GU2 7XH, UK
We consider a quantum system consisting of a regular chain of
elementary subsystems with nearest neighbour interactions and
form groups of N subsystems each.
Assuming that the total system is in a canonical state
ρ = exp(H / k T) / Z with temperature T we analyse under
what condition the state may be decomposed into a product of
canonical density matrices of the subgroups,
ρ′ = ∏i exp(Hi / k T) / Zi, with the same
temperature T.
We then compare the classical and the quantum regime and
apply our analysis to a harmonic chain as an example.