Quantum phase amplification
Giacomo Mauro D’Ariano, Chiara Macchiavello, Nicoletta Sterpi, Horace P. Yuen · Physical Review A · 1996
A scheme for amplifying phase shifts is presented, based on ideal photon number deamplification. For high-sensitivity measurements phase amplification sizeably reduces the bit-error rate and enhances the mutual information retrieved from the measurement. Phase-coherent states preserve their coherence under amplification, and achieve the best amplifier performance. \textcopyright{} 1996 The American Physical Society.