Progress in the nondestructive measurement of states in quantum communication and computation systems

摘要

We discuss methodologies for non-demolition measurement of quantum states. Four quantum non-demolition measurement strategies are described namely phase-coupled, polarization-coupled, gain-coupled, and Raman-effect coupled measurement schemes. Qualitative as well as quantitative assessments are presented for each of the measurement schemes in terms of back-action evading, quantum-state preparation, and degradation of signal field. Simulation results indicate that quantum non-demolition measurements are realized for low coupling coefficients for each of the four schemes.