The Quantum Heisenberg Ferromagnet can be naturally reformulated in terms of interacting bosons (called spin waves or magnons) as an expansion in the inverse spin size. We calculate the first order interaction correction to the free energy, as an upper bound in the limit where the spin size S -> infinity and beta S is fixed (beta being the inverse temperature). Our result is valid in two and three spatial dimensions. We extrapolate our result to compare with Dyson's low-temperature expansion. While our first-order correction has the expected temperature dependence, in higher orders of the perturbation theory cancellations are necessary.
Interaction Corrections to Spin-Wave Theory in the Large-S Limit of the Quantum Heisenberg Ferromagnet / N. Benedikter. - In: MATHEMATICAL PHYSICS ANALYSIS AND GEOMETRY. - ISSN 1385-0172. - 20:2(2017), pp. 5.1-5.21. [10.1007/s11040-016-9237-6]
Interaction Corrections to Spin-Wave Theory in the Large-S Limit of the Quantum Heisenberg Ferromagnet
N. Benedikter
2017
Abstract
The Quantum Heisenberg Ferromagnet can be naturally reformulated in terms of interacting bosons (called spin waves or magnons) as an expansion in the inverse spin size. We calculate the first order interaction correction to the free energy, as an upper bound in the limit where the spin size S -> infinity and beta S is fixed (beta being the inverse temperature). Our result is valid in two and three spatial dimensions. We extrapolate our result to compare with Dyson's low-temperature expansion. While our first-order correction has the expected temperature dependence, in higher orders of the perturbation theory cancellations are necessary.File | Dimensione | Formato | |
---|---|---|---|
spinwave.pdf
accesso aperto
Tipologia:
Pre-print (manoscritto inviato all'editore)
Dimensione
450.54 kB
Formato
Adobe PDF
|
450.54 kB | Adobe PDF | Visualizza/Apri |
Benedikter2017_Article_InteractionCorrectionsToSpin-W.pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
399.59 kB
Formato
Adobe PDF
|
399.59 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.