论文标题
量子参考框架中的相对论铃铛测试
Relativistic Bell Test within Quantum Reference Frames
论文作者
论文摘要
在相对论量子信息领域中，仍然有一个广泛争议的问题是，纠缠和违反贝尔对大规模相对论粒子不平等的程度是否独立于框架。这个问题的核心是旋转与相对论速度的动量自由程度纠缠在一起的效果。在这里，我们表明，即使没有任何颗粒动量后，贝尔的一对颗粒的不平等也可能会在特殊的重复性方面受到最大侵犯。为此，我们使用量子参考框架的方法，这使我们能够将问题转换为粒子的其余框架，从实验室框架的角度来看，粒子可以在相对论力量的叠加中。我们表明，当两个粒子的相对运动是非共线的时，在实验室框架中违反贝尔的不平等的最佳测量值涉及“连贯的Wigner旋转”。此外，违反贝尔不平等的程度与量子参考框架的选择无关。我们的结果开辟了将基于纠缠的量子通信协议扩展到相对论制度的可能性。
A still widely debated question in the field of relativistic quantum information is whether entanglement and the degree of violation of Bell's inequalities for massive relativistic particles are frame independent or not. At the core of this question is the effect that spin gets entangled with the momentum degree of freedom at relativistic velocities. Here, we show that Bell's inequalities for a pair of particles can be maximally violated in a special-relativistic regime, even without any post-selection of the momentum of the particles. To this end, we use the methodology of quantum reference frames, which allows us to transform the problem to the rest frame of a particle, whose state can be in a superposition of relativistic momenta from the viewpoint of the laboratory frame. We show that, when the relative motion of two particles is non-collinear, the optimal measurements for violation of Bell's inequalities in the laboratory frame involve "coherent Wigner rotations". Moreover, the degree of violation of Bell's inequalities is independent of the choice of the quantum reference frame. Our results open up the possibility of extending entanglement-based quantum communication protocols to relativistic regimes.
