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arXiv · 1010.1816

Dynamic Many-Body Theory. II. Dynamics of Strongly Correlated Fermi Fluids

H. M. Böhm·R. Holler·E. Krotscheck·M. Panholzer
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Abstract

We develop a systematic theory of multi-particle excitations in strongly interacting Fermi systems. Our work is the generalization of the time-honored work by Jackson, Feenberg, and Campbell for bosons, that provides, in its most advanced implementation, quantitative predictions for the dynamic structure function in the whole experimentally accessible energy/momentum regime. Our view is that the same physical effects -- namely fluctuations of the wave function at an atomic length scale -- are responsible for the correct energetics of the excitations in both Bose and Fermi fluids. Besides a comprehensive derivation of the fermion version of the theory and discussion of the approximations made, we present results for homogeneous He-3 and electrons in three dimensions. We find indeed a significant lowering of the zero sound mode in He-3 and a broadening of the collective mode due to the coupling to particle-hole excitations in good agreement with experiments. The most visible effect in electronic systems is the appearance of a ``double-plasmon'' excitation.

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H. M. Böhm, R. Holler, E. Krotscheck, M. Panholzer. 2010-10-09. Dynamic Many-Body Theory. II. Dynamics of Strongly Correlated Fermi Fluids. https://doi.org/10.1103/physrevb.82.224505

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