Quasiparticle Lifetime in a Finite System: A Non–Perturbative Approach

Дата и время публикации : 1996-09-15T01:26:07Z

Авторы публикации и институты :
B. L. Altshuler (NEC)
Y. Gefen (Weizmann Inst.)
A. Kamenev (Weizmann Inst.)
L. S. Levitov (MIT)

Ссылка на журнал-издание: Phys. Rev. Lett. 78, 2803 (1997)
Коментарии к cтатье: 13 pages, LaTeX, one figure
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: The problem of electron–electron lifetime in a quantum dot is studied beyond perturbation theory by mapping it onto the problem of localization in the Fock space. We identify two regimes, localized and delocalized, corresponding to quasiparticle spectral peaks of zero and finite width, respectively. In the localized regime, quasiparticle states are very close to single particle excitations. In the delocalized state, each eigenstate is a superposition of states with very different quasiparticle content. A transition between the two regimes occurs at the energy $simeqDelta(g/ln g)^{1/2}$, where $Delta$ is the one particle level spacing, and $g$ is the dimensionless conductance. Near this energy there is a broad critical region in which the states are multifractal, and are not described by the Golden Rule.

Category: Physics