Creation of a spin squeezing state using an interacting spin system

Quantum information technology has shown promising applications in various fields, including computing, communication and sensing. The capability of the technology is ultimately limited by how precisely quantum mechanical observables can be determined in the measurement, and various ways to improve the precision of quantum measurements has been proposed and demonstrated. Among the methods, the measurement using a quantum squeezing state is promising to reduce the uncertainty of the measurement beyond the standard quantum limit (SQL). The measurement with a squeezing state of photons has been employed in the detectors of the Laser Interferometer Gravitational-Wave Observatory and the improved sensitivity has been demonstrated successfully. In this presentation, we discuss a method of the generation of a spin squeezing state using an interaction spin system. We show that the Hamiltonian of the interaction spin system can be expressed as an one-axis twisting (OAT) Hamiltonian, and the resultant state is a squeezed state. We will also discuss how to implement the quantum measurement with a spin squeezed state in a spin system based a nitrogen-vacancy (NV) center in diamond [1].