Continuous quantum measurements: Restricted path integrals and master equations

Abstract

The relation between two mathematical techniques in the theory of continuous quantum measurements is considered, one of them based on restricted path integrals (RPI) and the other one on master equations (ME). A typical continuous quantum measurement, monitoring an arbitrary observable, is presented for both techniques. This demonstrates mathematical equivalence of RPI and ME methods. Efficiency (reducibility to imaginary terms in a Hamiltonian) and generality (independence of the model of the RPI method) are argued.