On 4-point correlation functions in simple polymer models

Johannes-Geert Hagmann (1) , Karol K. Kozlowski (1) , Nikos Theodorakopoulos (2) , Michel Peyrard (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 Theoretical and Physical Chemistry Institute NHRF

We derive an exact formula for the covariance of cartesian distances in two simple polymer models, the freely-jointed chain and a discrete flexible model with nearest-neighbor interaction. We show that even in the interaction-free case correlations exist as long as the two distances at least partially share the same segments. For the interacting case, we demonstrate that the naive expectation of increasing correlations with increasing interaction strength only holds in a finite range of values. Some suggestions for future single-molecule experiments are made.

Mots clés: 4-point correlations; polymers

Domaines: Matière Molle [cond-mat.soft]; Mécanique statistique [cond-mat.stat-mech]

Johannes-Geert Hagmann, Karol K. Kozlowski, Nikos Theodorakopoulos, Michel Peyrard. On 4-point correlation functions in simple polymer models. Journal of Statistical Mechanics: Theory and Experiment, 2009, pp.P04011. ⟨10.1088/1742-5468/2009/04/P04011⟩. ⟨hal-00370639v2⟩