Chen, LiZhang, YunboPu, Han2020-10-282020-10-282020Chen, Li, Zhang, Yunbo and Pu, Han. "Spin squeezing in a spin-orbit-coupled Bose-Einstein condensate." <i>Physical Review A,</i> 102, no. 2 (2020) American Physical Society: https://doi.org/10.1103/PhysRevA.102.023317.https://hdl.handle.net/1911/109453We study the spin squeezing in a spin-1/2 Bose-Einstein condensates (BEC) with Raman-induced spin-orbit coupling (SOC). Under the condition of two-photon resonance and weak Raman coupling strength, the system possesses two degenerate ground states, using which we construct an effective two-mode model. The Hamiltonian of the two-mode model takes the form of the one-axis-twisting Hamiltonian, which is known to generate spin squeezing. More importantly, we show that the SOC provides a convenient control knob to adjust the spin nonlinearity responsible for spin squeezing. Specifically, the spin nonlinearity strength can be tuned to be comparable to the two-body density-density interaction, and hence is much larger than the intrinsic spin-dependent interaction strength in conventional two-component BEC systems such as 87Rb and 23Na in the absence of the SOC. We confirm the spin squeezing by carrying out a fully beyond-mean-field numerical calculation using the truncated Wigner method. Additionally, the experimental implementation is also discussed.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttps://doi.org/10.1103/PhysRevA.102.023317