MEASUREMENTS AND CORRELATIONS IN TRI-PARTITE SYSTEMS

Abstract

A system comprised of three oscillators A, B and C is studied. The oscillators B and C are interacting with each other, while the oscillator A does not interact with any of them. At t = 0 the system is in the state ρAB(0) ⊗ ρC(0). Two examples in which ρAB(0) is in separable and entangled states, are considered. It is shown that the oscillators A, C become entangled and that a measurement in C whose result is communicated classically to A , affects the state of the oscillator A. The work studies how the collapse due to the measurement at C , affects the state of the oscillator A .