Workshop on Cold Atom Physics and Quantum Information for Young Researchers Ferromagnetism in Bose Systems Qiang Gu Department of Physics University of Science and Technology Beijing (USTB) Taiyuan, July 4, 2007
Ferromagnetism in Bose Systems Qiang Gu Department of Physics University of Science and Technology Beijing (USTB) Taiyuan, July 4, 2007 Workshop on Cold Atom Physics and Quantum Information for Young Researchers
Outline Historical introduction to ferromagnetism Curie point of ferromagnetic Bose gas Thermodynamics of ferromagnetic Bose gas Spin aynamics in ferromagnetic condensates Brief summary
Outline • Historical introduction to ferromagnetism • Curie point of ferromagnetic Bose gas • Thermodynamics of ferromagnetic Bose gas • Spin dynamics in ferromagnetic condensates • Brief summary
Historical introduction to ferromagnetism
Historical introduction to ferromagnetism
Historical introduction 625-564b.c. Earliest known reference to magnetism Thales(台利斯)- Greek philosopher& mathematician In China: magnetite(cishi )mentioned in Guanzi by GI uan Lions g(管仲) before200b.c. 1086 First known application Shen Kuo(沈括) Meng Chhi pi than lodestone used as compass by Chinese since 7th-8th) In Europe: compass first mentioned by Neckam in 1187 P Mohn, Magnetism in the Solid State: An Introduction(Springer-Verlag, Berlin, 2003)
Historical introduction 625-564b.c. Earliest known reference to magnetism Thales (台利斯)--Greek philosopher & mathematician In China: magnetite (cishi) mentioned in Guanzi by Guan Zhong (管仲) before 200b.c. 1086 First known application Shen Kuo(沈括) Meng Chhi Pi Than lodestone used as compass by Chinese since 7th-8th) In Europe: compass first mentioned by Neckam in 1187 P. Mohn, Magnetism in the Solid State: An Introduction (Springer-Verlag, Berlin, 2003)
Historical introduction ate l9th o early 20th Properties of magnets 1895 P Curie linear T-dependence of inverse susceptibility 1905 P. Langevin Theoretical explanation of Curie law langevin diamagnetism 1907 P. Weiss molecular field theory of ferromagnetism C x T T-6 Curie law Curie-Weiss law(1907) 1928 Heisenberg model 1932-36 Neel Generalied Weiss theory for antiferromagnets
Historical introduction Late 19th ~ early 20th Properties of magnets 1895 P. Curie Linear T-dependence of inverse susceptibility 1905 P. Langevin Theoretical explanation of Curie law & Langevin diamagnetism 1907 P. Weiss Molecular field theory of ferromagnetism 1928 Heisenberg Model 1932-36 Neel Generalied Weiss theory for antiferromagnets Curie law Curie-Weiss law (1907)