Institut für Theoretische Physik, Universität Innsbruck, A-6020 Innsbruck, Austria.
Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan.
Phys Rev Lett. 2023 Mar 3;130(9):090802. doi: 10.1103/PhysRevLett.130.090802.
We predict that exploiting spin-orbit coupling in a harmonically trapped spinor quantum gas can lead to scaling of the optimal measurement precision beyond the Heisenberg scaling. We show that quadratic scaling with the number of atoms can be facilitated via squeezed center-of-mass excitations of the atomic motion using 1D spin-orbit coupled fermions or strongly interacting bosons (Tonks-Girardeau gas). Based on predictions derived from analytic calculations of the corresponding quantum Fisher information, we then introduce a protocol which overcomes the Heisenberg scaling (and limit) with the help of a tailored excited and entangled many-body state of a noninteracting Bose-Einstein condensate. We identify corresponding optimal measurements and argue that even finite temperature as a source of decoherence is, in principle, rather favorable for the obtainable precision scaling.
我们预测，在受谐波约束的自旋量子气体中利用自旋轨道耦合可以实现超越海森堡极限的最优测量精度的标度。我们表明，通过使用一维自旋轨道耦合费米子或强相互作用玻色子（Tonks-Girardeau 气体）对原子运动的质心压缩激发，可以实现与原子数的二次方标度。基于对相应量子 Fisher 信息的解析计算的预测，我们然后引入了一种协议，该协议借助非相互作用玻色-爱因斯坦凝聚体的定制激发和纠缠的多体状态克服了海森堡极限（和限制）。我们确定了相应的最优测量，并认为即使是作为退相干源的有限温度，原则上对于可获得的精度标度也是相当有利的。
