کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8154675 | 1524802 | 2016 | 29 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Thermodynamic properties of the 2D frustrated Heisenberg model for the entire J1-J2 circle
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Using the spherically symmetric self-consistent Green's function method, we consider thermodynamic properties of the S=1/2J1-J2 Heisenberg model on the 2D square lattice. We calculate the temperature dependence of the spin-spin correlation functions cr=ãS0zSrzã, the gaps in the spin excitation spectrum, the energy E and the heat capacity CV for the whole J1-J2-circle, i.e. for arbitrary Ï, J1=cos(Ï), J2=sin(Ï). Due to low dimension there is no long-range order at Tâ 0, but the short-range holds the memory of the parent zero-temperature ordered phase (antiferromagnetic, stripe or ferromagnetic). E(Ï) and CV(Ï) demonstrate extrema “above” the long-range ordered phases and in the regions of rapid short-range rearranging. Tracts of cr(Ï) lines have several nodes leading to nonmonotonic cr(T) dependence. For any fixed Ï the heat capacity CV(T) always has maximum, tending to zero at Tâ0, in the narrow vicinity of Ï=155° it exhibits an additional frustration-induced low-temperature maximum. We have also found the nonmonotonic behaviour of the spin gaps at Ï=270°±0 and exponentially small antiferromagnetic gap up to (Tâ²0.5) for Ïâ³270°.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 419, 1 December 2016, Pages 131-139
Journal: Journal of Magnetism and Magnetic Materials - Volume 419, 1 December 2016, Pages 131-139
نویسندگان
A.V. Mikheyenkov, A.V. Shvartsberg, V.E. Valiulin, A.F. Barabanov,