Supersymmetric field theory of a non-equilibrium stochastic system as applied to random heteropolymers

A supersymmetric field scheme is derived based on the Langevin equation whi ch enables memory and non-ergodicity effects in a nonequilibrium stochastic system with quenched disorder to be described in an optimal manner. This s cheme is applied to a random heteropolymer, whose effective Hamiltonian is found to be simply the free energy as a function of the compositional order parameter. Instead of the Langevin equation, an effective equation of moti on is used to describe the way different monomers alternate as they move al ong a polymer chain. The isothermal and adiabatic susceptibilities, memory parameter, and irreversible response to temperature are determined as funct ions of the temperature and of the amount of quenched disorder.