标题： 原子干涉仪是否在康普顿频率上测试引力红移？ 显示英文标题

标题： Does an atom interferometer test the gravitational redshift at the Compton frequency ?

摘要： 原子干涉仪允许测量自由下落的原子相对于静止于地球表面的实验平台的加速度。 此类实验曾被用来通过比较原子的加速度与经典自由下落物体的加速度来检验自由落体的普适性。 在近期的一篇论文中，Müller、Peters 和 Chu [《自然》,{\bf 463}, 926-929 (2010)] 认为，当把原子视为以静质量相关的康普顿频率运行的时钟时，原子干涉仪同样可以非常精确地测试引力红移效应。 我们在广义相对论框架以及不同的替代理论框架下分析了这一主张。 我们表明，在包括广义相对论、所有度规引力理论、大多数非度规引力理论和大多数用于解释等效原理违反现象的理论框架在内的大类理论中，干涉仪两条路径之间“康普顿相位”的差异实际上为零。 因此，在大多数合理的理论框架中，不存在红移效应，原子干涉仪仅仅测试了自由落体的普适性。 我们还表明，那些认为原子干涉仪可以测试红移效应的框架存在严重问题，例如：(i) 违背Schiff猜想，(ii) 违背量子力学中的Feynman路径积分表述和物质波的最小作用原理，(iii) 违背能量守恒，更广泛地说(iv) 违背量子力学中的粒子-波二象性。 在这种情况下，标准量子力学不再成立，因此对该实验的一致性解释需要量子力学的替代表述。 由于到目前为止尚未提出这样的替代方案，我们得出结论，将原子干涉仪解释为测试引力红移效应是站不住脚的。 显示英文摘要

摘要： Atom interferometers allow the measurement of the acceleration of freely falling atoms with respect to an experimental platform at rest on Earth's surface. Such experiments have been used to test the universality of free fall by comparing the acceleration of the atoms to that of a classical freely falling object. In a recent paper, M\"uller, Peters and Chu [Nature {\bf 463}, 926-929 (2010)] argued that atom interferometers also provide a very accurate test of the gravitational redshift when considering the atom as a clock operating at the Compton frequency associated with the rest mass. We analyze this claim in the frame of general relativity and of different alternative theories. We show that the difference of "Compton phases" between the two paths of the interferometer is actually zero in a large class of theories, including general relativity, all metric theories of gravity, most non-metric theories and most theoretical frameworks used to interpret the violations of the equivalence principle. Therefore, in most plausible theoretical frameworks, there is no redshift effect and atom interferometers only test the universality of free fall. We also show that frameworks in which atom interferometers would test the redshift pose serious problems, such as (i) violation of the Schiff conjecture, (ii) violation of the Feynman path integral formulation of quantum mechanics and of the principle of least action for matter waves, (iii) violation of energy conservation, and more generally (iv) violation of the particle-wave duality in quantum mechanics. Standard quantum mechanics is no longer valid in such frameworks, so that a consistent interpretation of the experiment would require an alternative formulation of quantum mechanics. As such an alternative has not been proposed to date, we conclude that the interpretation of atom interferometers as testing the gravitational redshift is unsound.