Quantum nondemolition measurements of a qubit coupled to a harmonic oscillator
Quantum nondemolition measurements of a qubit coupled to a harmonic oscillator
We theoretically describe the weak measurement of a two-level system (qubit) and quantify the degree to which such a qubit measurement has a quantum nondemolition (QND) character. The qubit is coupled to a harmonic oscillator, which undergoes a projective measurement. Information on the qubit state is extracted from the oscillator …