Heisenberg-limited spin squeezing in coupled spin systems

Spin squeezing plays a crucial role in quantum metrology and quantum information science. Its generation is the prerequisite for further applications but still faces an enormous challenge since the existing physical systems rarely contain the required squeezing interactions. Here we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions, which commonly exist in various systems. Our scheme can transform the coupled spin interactions into squeezing interactions and reach the extreme squeezing with Heisenberg-limited measurement precision scaling as 1/N for N particles. Only constant and continuous driving fields are required, which is a requirement that is accessible to a series of current realistic experiments. This work greatly enriches the variety of systems that can generate the Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement.

Automated summary

Spin squeezing is crucial for quantum metrology and quantum information science, but its generation faces challenges due to the lack of squeezing interactions in existing physical systems. In this study, we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions. We can transform the coupled spin interactions into squeezing interactions and achieve extreme squeezing with Heisenberg-limited measurement precision scaling as 1/N for N particles. Only constant and continuous driving fields are required, making it accessible for current realistic experiments. This work greatly expands the systems capable of generating Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement.