Modern Physics Letters B
QUANTUM STOCHASTIC HEISENBERG EQUATION
Takeshi Saito, Toshihico Arimitsu
Abstract
By extending the quantum stochastic Liouville equation formulated by one of the authors (T. A.) within Non-Equilibrium Thermo Field Dynamics (NETFD), it is shown that, by means of stochastic Heisenberg equation, one can construct a unified framework of stochastic differential equations for quantum systems with the quantum white noise of non-thermal ensemble. A new aspect is given to deal with the difficulties attending quantum Langevin equations.