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We present a simple and effective method to create highly entangled spin states on a faster timescale than that of the commonly employed one-axis twisting (OAT) model. We demonstrate that by periodically driving the Dicke Hamiltonian at a resonance frequency, the system effectively becomes a two-axis countertwisting Hamiltonian, which is known to quickly create Heisenberg limit scaled entangled states. For these states we show that simple quadrature measurements can saturate the ultimate precision limit for parameter estimation determined by the quantum Cramér-Rao bound. An example experimental realization of the periodically driven scheme is discussed with the potential to quickly generate momentum entanglement in a recently described experimental vertical cavity system. We analyze effects of collective dissipation in this vertical cavity system and find that our squeezing protocol can be more robust than the previous realization of OAT. Published by the American Physical Society2024 

Abstract We present a test of Coasean theories of efficient separations. We study a cohort of jobs from the introduction through the repeal of a large age- and region-specific unemployment benefit extension in Austria. In the treatment group, 18.5$$\%$$ fewer jobs survive the program period. According to the Coasean view, the destroyed marginal jobs had low joint surplus. Hence, after the repeal, the treatment survivors should be more resilient than the ineligible control group survivors. Strikingly, the two groups instead exhibit identical post-repeal separation behaviour. We provide, and find suggestive evidence consistent with, an alternative model in which wage rigidity drives the inefficient separation dynamics.