Hannover 2010 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 8: Poster I

A 8.2: Poster

Dienstag, 9. März 2010, 16:30–19:00, Lichthof

Shortcomings of Lindemann-like melting criteria in finite systems — •Jens Böning, Torben Ott, and Michael Bonitz — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität, Leibnizstr. 15, D-24098 Kiel, Germany

For numerical studies of phase transitions, a rich variety of so called Lindemann and Lindemann-like criteria exists. Their popularity is mostly due to their simplicity, especially for numerical implementation. They are found to work reasonably well even in finite few-particle systems where no strict phases exist [1], which is also reflected in a softening in other melting criteria like the specific heat or magnetic moment. In this work, we provide an overview over available Lindemann-like parameters and their limitations. We focus on the mean relative distance fluctuations also known as Berry parameter which is often seen as Lindemann-like but differs fundamentally [2]. We demonstrate that this parameter is inherently flawed and requires renormalization to a universal time-scale [3].

[1] F. Baletto and R. Ferrando, Rev. Mod. Phys. 77, 371 (2005)

[2] D.D. Frantz, J. Chem. Phys. 115, 6136 (2001)

[3] J. Böning et al., Phys. Rev. Lett. 100, 113401 (2008)