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Polynomial method for canonical calculations

N. K. Kuzmenko·V. M. Mikhajlov
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Abstract

A practical version of the polynomial canonical formalism is developed for normal mesoscopic systems consisting of N independent electrons. Drastic simplification of calculations is attained by means of proper ordering excited states of the system. In consequence the exact canonical partition function can be represented as a series in which the first term corresponds to the ground state whereas successive groups of terms belong to many particle-hole excitations (one particle-hole two particle-hole and so on). At small temperatures (T<10 inter-level spacings near the Fermi level) the number of terms which should be taken into account is weakly dependent on N and remains <10 even if N~100000. The elaborated method makes canonical calculations to be not more complicated than the grand canonical ones and is free from any limitations on N and T.

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N. K. Kuzmenko, V. M. Mikhajlov. 2004-04-13. Polynomial method for canonical calculations. https://arxiv.org/abs/cond-mat/0404299

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