TY - JOUR

T1 - Magnetic properties of some itinerant-electron systems at T>0

AU - Aizenman, Michael

AU - Lieb, Elliott

PY - 1990/1/1

Y1 - 1990/1/1

N2 - The Lieb-Mattis theorem on the absence of one-dimensional ferromagnetism is extended here from ground states to T>0 by proving, inter alia, that M the magnetization of a quantum system in a field h>0, is always less than the pure paramagnetic value M0=tanh with =1/kT. Our proof rests on a new formulation in terms of path integrals that holds in any dimension; another of its applications is that the Nagaoka-Thouless theorem on the Hubbard model also extends to T>0 in the sense that Mexceeds M0.

AB - The Lieb-Mattis theorem on the absence of one-dimensional ferromagnetism is extended here from ground states to T>0 by proving, inter alia, that M the magnetization of a quantum system in a field h>0, is always less than the pure paramagnetic value M0=tanh with =1/kT. Our proof rests on a new formulation in terms of path integrals that holds in any dimension; another of its applications is that the Nagaoka-Thouless theorem on the Hubbard model also extends to T>0 in the sense that Mexceeds M0.

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U2 - 10.1103/PhysRevLett.65.1470

DO - 10.1103/PhysRevLett.65.1470

M3 - Article

C2 - 10042274

AN - SCOPUS:0001239224

VL - 65

SP - 1470

EP - 1473

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 12

ER -