Summary
An infinite system of interacting bosons at temperatureT=0 is studied by a first-order self-consistent method. It is shown that such system may exhibit condensation in single-particle states or in more-particle states. The condensation in one or the other state depends on the interaction potential. Then we analyse the existence or other-wise of the gap in the excitation spectrum making use of theorems valid for systems which exhibit a broken symmetry.
Riassunto
Facendo uso di un metodo autocompatibile al primo ordine viene studiato un sistema infinito di bosoni interagenti a temperaturaT=0. Si mostra che tale sistema può presentare condensazione in uno stato di singole particelle o di più particelle. La condensazione nell’uno o nell’altro stato dipende dal potenziale di interazione. Si analizza poi l’esistenza o meno di un «gap» nello spettro dell’energia sulla base di teoremi validi in sistemi che presentano rottura di simmetria.
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References
H. Umezawa:Acta Phys. Hung.,19, 9 (1965).
O. Penrose andL. Onsager:Phys. Rev.,104, 576 (1956);C. N. Yang:Rev. Mod. Phys.,34, 694 (1962).
M. Girardeau andM. Arnowitt:Phys. Rev.,113, 755 (1959).
F. Takano:Phys. Rev.,123, 499 (1961).
M. Luban:Phys. Rev.,128, 965 (1962).
P. C. Hoenberg:Thesis, presented for Ph. D. (1962) unpublished.
P. Szepfalusy:Acta Phys. Hung.,19, 109 (1965).
See for example ref. (14,3,4) andM. Girardeau:Phys. Rev.,115, 1090 (1959).
A. Katz andY. Frishman: preprint (1966), Weizmann Institute of Science Rehovoth.
L. Leplae, R. N. Sen andH. Umezawa:Progr. Theor. Phys. Suppl., extra number, 637 (1965);L. Leplae andH. Umezawa: preprint (1966), Università di Napoli.
H. Araki andE. J. Woods:Journ. Math. Phys.,4, 637 (1963).
H. Ezawa andM. Luban: preprint (1966), University of Wisconsin, Milwaukee. Wis.
The possibility of such solutions was shown also byC. Di Castro in his Thesis (Università di Roma 1961).
N. M. Hugenholtz andD. Pines:Phys. Rev.,116, 489 (1959).
N. N. Bogoliubov:Journ. Phys. Moscow,11, 23 (1947); reprinted inD. Pines, Ed.:The Many-Body Problem (New York).
S. T. Beliaev:Sov. Phys. JETP:7, 289, 299 (1958).
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This research has been sponsored in part by the Gruppo di Napoli of the GNSM.
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Coniglio, A., Marinaro, M. On condensation for an interacting boson system. Nuovo Cimento B (1965-1970) 48, 249–261 (1967). https://doi.org/10.1007/BF02712190
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DOI: https://doi.org/10.1007/BF02712190