title: Spin-oscillator model for the unzipping of biomolecules by mechanical force.
abstract: A spin-oscillator system models unzipping of biomolecules (such as DNA, RNA, or proteins) subject to an external force. The system comprises a macroscopic degree of freedom, represented by a one-dimensional oscillator, and internal degrees of freedom, represented by Glauber spins with nearest-neighbor interaction and a coupling constant proportional to the oscillator position. At a critical value F(c) of an applied external force F, the oscillator rest position (order parameter) changes abruptly and the system undergoes a first-order phase transition. When the external force is cycled at different rates, the extension given by the oscillator position exhibits a hysteresis cycle at high loading rates, whereas it moves reversibly over the equilibrium force-extension curve at very low loading rates. Under constant force, the logarithm of the residence time at the stable and metastable oscillator rest position is proportional to F-F(c) as in an Arrhenius law.
authors.affiliation: Física Teórica, Universidad de Sevilla Apartado de Correos 1065, E-41080 Sevilla, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Prados
authors.forename: A
authors.initials: A
authors.lastname: Carpio
authors.forename: L L
authors.initials: LL
authors.lastname: Bonilla
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D017276:Friction; D055595:Mechanical Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D009010:Monte Carlo Method; D017711:Nonlinear Dynamics; D013269:Stochastic Processes; D013696:Temperature
chemical_list: D001704:Biopolymers