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Numerical study of quasiparticle lifetime in quantum dots

Alejandro M. F. Rivas·Eduardo R. Mucciolo·Alex Kamenev
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Abstract

The decay rate of quasiparticles in quantum dots is studied through the real time calculation of the single-particle Green function in the self-consistent approximation. The method avoids exact diagonalization, transforming the problem into a system of coupled non-linear integral equations which may be solved iteratively. That allows us to study systems larger than previously treated in the literature. Our results for the inverse participation ratio of many-body states show that the threshold energy for the quasiparticle disintegration is $E^\ast \sim \sqrt{g} Δ$. The delocalization transition is soft rather than sharp. Three different regimes as function of the effective interaction strength may be clearly identified at high energies.

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Alejandro M. F. Rivas, Eduardo R. Mucciolo, Alex Kamenev. 2001-09-25. Numerical study of quasiparticle lifetime in quantum dots. https://doi.org/10.1103/physrevb.65.155309

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