论文标题
超长量子通过自旋轨光子学步行
Ultra-long quantum walks via spin-orbit photonics
论文作者
论文摘要
微调光学模式之间的耦合的可能性是光子电路中量子模拟的关键要求。在这些体系结构中，模拟颗粒在大晶格中的长时间演变需要复杂的设置，这些设置通常本质上是有损的。在这里，我们报告了几百个光学模式的超长光子量子行走，通过在很少有堆叠的液体晶体元整座中传播光束来获得。通过利用自旋轨道效应，这些实现了依赖于空间的极化变换，这些变换将带有量化横向动量的圆极化光学模式混合。当每个跨表面在遥远模式之间实现远程耦合时，仅使用其中一些，我们模拟了量子步行最多320个离散步骤，而无需任何光学放大，而远远超出了最新的实验。为了展示这种方法的潜力，我们实验表明，在长期限制下，受动力障碍影响的量子步行会产生两个系统分区之间的最大纠缠。我们的平台授予实验性访问大规模统一演变的访问，同时将光损失保持在最低限度，从而为大规模多光子多模式量子模拟铺平了道路。
The possibility of fine-tuning the couplings between optical modes is a key requirement in photonic circuits for quantum simulations. In these architectures, emulating the long-time evolution of particles across large lattices requires sophisticated setups, that are often intrinsically lossy. Here we report ultra-long photonic quantum walks across several hundred optical modes, obtained by propagating a light beam through very few closely-stacked liquid-crystal metasurfaces. By exploiting spin-orbit effects, these implement space-dependent polarization transformations that mix circularly polarized optical modes carrying quantized transverse momentum. As each metasurface implements long-range couplings between distant modes, by using only a few of them we simulate quantum walks up to 320 discrete steps without any optical amplification, far beyond state-of-the-art experiments. To showcase the potential of this method, we experimentally demonstrate that in the long-time limit a quantum walk affected by dynamical disorder generates maximal entanglement between two system partitions. Our platform grants experimental access to large-scale unitary evolutions while keeping optical losses at a minimum, thereby paving the way to massive multi-photon multi-mode quantum simulations.
