Quantum Optical Metrology Using Entangled Photonic States

Abstract

Quantum metrology is one of the most sophisticated disciplines of quantum technologies. The primary purpose of this research domain is to investigate unknown physical quantities by using quantum mechanical resources. Quantum metrology has an extensive range of applications including, in the development of quantum sensors, photonic quantum systems, and various metrological tasks. Quantum resources have shown better improvement in phase estimation as compared to classical measurements which are limited by standard quantum limit. Quantum entanglement has been considered one of the counter-intuitive concepts in quantum physics which has played a vital role in overcoming the standard quantum limit. Herein we have deployed the quantum Fisher information approach and used various quantum mechanical states for phase estimation. Our main focus was using squeezed states in different modes to develop ways for quantum metrology. We have found better results that surpass the shot-noise limit and approach the more fundamental Heisenberg’s limit in modified structures with given schemes. Moreover, we have introduced an entangled squeezed vacuum state (ESVS) as the best quantum resource for phase estimation. This research aims to contribute to the area of precision measurements and hence to develop photonic quantum sensing.