Regensburg 2004 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 5: Computational Physics

CPP 5.4: Vortrag

Montag, 8. März 2004, 10:45–11:00, H 39

Collapse of Long Lattice Polymers — •Thomas Vogel, Michael Bachmann, and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig, Germany

Using the nPERM algorithm [1], we have investigated long polymer chains on the simple cubic lattice in three and four dimensions. At the so-called θ-point, there is a second-order phase transition from a globular state to a coil-like state predicted from mean-field theory. Surprisingly, for finite chains, in four dimensions this transition looks first-order-like [2]. We investigate this pseudo-first-order transition by means of thermodynamic quantities such as the end-to-end distance and the radius of gyration.

We will also report some details about the behaviour of the PERM algorithm we found by analysing energy distributions near the critical temperature and how to avoid strong correlations between growing chains.

[1] P. Grassberger, Phys. Rev. E 56 (1997) 3682; H.-P. Hsu, V. Mehra, W. Nadler, P. Grassberger, J. Chem. Phys. 118 (2002) 444.

[2] T. Prellberg, A.L. Owczarek, Phys. Rev. E 62 (2000) 3780.