Time-dependent screening of a positive charge distribution in metals: Excitons on an ultra-short time scale

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Schöne, Wolf-Dieter ; Ekardt, Walter (2000)

Experiments determining the lifetime of excited electrons in crystalline copper reveal states which cannot be interpreted as Bloch states [S. Ogawa {\it et al.}, Phys. Rev. B {\bf 55}, 10869 (1997)]. In this article we propose a model which explains these states as transient excitonic states in metals. The physical background of transient excitons is the finite time a system needs to react to an external perturbation, in other words, the time which is needed to build up a polarization cloud. This process can be probed with modern ultra-short laser pulses. We calculate the time-dependent density-response function within the jellium model and for real Cu. From this knowledge it is possible within linear response theory to calculate the time needed to screen a positive charge distribution and -- on top of this -- to determine excitonic binding energies. Our results lead to the interpretation of the experimentally detected states as transient excitonic states.
  • References (9)

    13 R. S. Knox, in Solid State Physics: Advances in Research and Applications, edited by H. Ehrenreich, F. Seitz, and D. Turnbull (Academic Press, New York, 1963), Suppl. 5.

    14 D. Pines and P. Nozi`eres, The Theory of Quantum Liquids, Addison-Wesley Publishing Company, Reading, 1988.

    15 N. W. Ashcroft and N. D. Mermin, Solid State Physics (Saunders College Publishing, Fort Worth, 1976).

    22 K. Burke and E.K.U. Gross, in Density functionals: Theory and applications, edited by D. Joubert (Springer, Berlin, 1998).

    23 A. G. Eguiluz, A. Fleszar, and J. A. Gaspar, Nuclear Instruments and Methods B 96, 550 (1995).

    24 G. S. Canright, Phys. Rev. B 38, 1647 (1988).

    25 W. Ku and A. G. Eguiluz, Phys. Rev. Lett. 82, 2350 (1999).

    26 J. P. Perdew and A. Zunger, Phys. Rev. B 23, 5048 (1981).

    27 I. Campillo, A. Rubio, and J. M. Pitarke, Phys. Rev. B 59, 12188 (1999).

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