Functional integral methods for quantum
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S Leibler; H Orland
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Article
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1981
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Elsevier Science
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English
โ 660 KB
The partition function of quantum spin systems is represented by a functional integral over "time"-dependent magnetic fields. It is evaluated in the saddle-point approximation. In this way, the excitations of the system are derived from first principles, and their interactions are obtained. ## 1. I