Quantum limits on phase-shift detection using multimode interferometers
Jonas Söderholm, Gunnar G. Bjork, Björn Hessmo, Shuichiro Inoue · Physical Review A · 2003
Fundamental phase-shift detection properties of optical multimode interferometers are analyzed. Limits on perfectly distinguishable phase shifts are derived for general quantum states of a given average energy. These bounds are found to be independent of the number of interfering modes, and are consistent with the Heisenberg limit. A short discussion on the concept of well-defined relative phase is also included.