Preparation of an arbitrary density matrix of a harmonic oscillator
C. K. Law, Joseph H. Eberly, B. Kneer · Journal of Modern Optics · 1997
We propose a deterministic method to generate an arbitrary (pure or mixed) density matrix of a harmonic oscillator. The general density matrices are achieved by manipulating quantum entanglement between the oscillator and an auxiliary oscillator. We discuss how our preparation scheme can be realized by cavity quantum electrodynamics interactions so that a general density matrix of a single-mode electromagnetic field can be created.