Quantum noise and quantum Langevin equations

Wen Wan

The properties of quantum noise and Langevin equation are discussed. Comparisons between the quantum noise and Langevin eqution and the classic one are presented. A brief derivation for quantum Langevin equation is showed. The quantum noise comes from two ways, namely, the way as same as that of classic noise and the Heisenberg uncertainty.

William C. Schieve, Lawrence Paul Horwitz

Crispin W. Gardiner

Horia I. Metiu, Gerd Schön

We derive an equation of motion for a fully observed classical system which is coupled to a quantum companion whose degrees of freedom are only partially observed. Our purpose is to discuss the nature of the quantum noise by using a generalization of the Langevin equation.

Crispin W. Gardiner, P. Zoller

FERDINANDO DE PASQUALE, Patrizia Ruggiero, Marco Zannetti

It is shown that the spectral density of the Ford-Kac-Mazur (1965) noise for the quantum Langevin equation can be derived from the general requirement of the validity of the fluctuation-dissipation theorem.