J. Ennis et al., Compression of a polymer chain by a small obstacle: The effect of fluctuations on the escape transition, PHYS REV E, 60(6), 1999, pp. 6906-6918
We describe the escape transition of an ideal chain compressed between fini
te-sized obstacles. Three different theoretical methods are used and each p
rovides a similar description of the escape transition, as predicted by ear
lier and less detailed mean-field theories. The first two methods show that
thermal fluctuations near the transition can blur what was previously desc
ribed as a sharp transition. The last method is an exact calculation of the
partition function that shows unambiguously the character of the escape tr
ansition. This exact calculation overcomes the inherent uncertainties assoc
iated with previous theory and computer simulation. [S1063-651X(99)04911-9]
.