Monte Carlo simulation of polymer chain with ferromagnetic Ising interaction

We consider a self-avoiding walking polymer chain with nearest-neighbor ferromagnetic Ising interaction (J>0) on the simple cubic lattice. The magnetic and conformational properties are simulated using Monte Carlo technique with bond-fluctuation model. Spontaneous magnetization is observed at low temperature. We estimate the critical temperature Tc=1.37±0.05(J/kB) and the critical exponents α≈0.42 and ν≈0.80 based on the finite-size scaling law. The values of α and ν are different from those of two- or three-dimensional Ising models, indicating that the phase transition in the Ising polymer chain model belongs to a different universality class. Near Tc, the chain also undergoes a collapse transition from random coil at T>Tc to compacted globule at T<Tc. We conclude that the phase transitions in the Ising polymer chain model result from the cooperation of configurational movement and the ferromagnetic Ising interaction.