Quantum gas microscopy of Kardar-Parisi-Zhang superdiffusion
Quantum gas microscopy of Kardar-Parisi-Zhang superdiffusion
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DOI：
10.1126/science.abk2397
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发表时间：
2021-06
期刊：
影响因子：
56.9
通讯作者：
David Wei;Antonio Rubio-Abadal;B. Ye;Francisco Machado;Jack Kemp;K. Srakaew;Simon Hollerith;Jun Rui;S. Gopalakrishnan;N. Yao;I. Bloch;J. Zeiher
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文献类型：
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作者：
David Wei;Antonio Rubio-Abadal;B. Ye;Francisco Machado;Jack Kemp;K. Srakaew;Simon Hollerith;Jun Rui;S. Gopalakrishnan;N. Yao;I. Bloch;J. Zeiher
Kardar-Parisi-Zhang（KPZ）的普遍性阶级描述了许多经典的随机模型的粗粒，KPZ的普遍性是在一个维量子Heisenberg模型中的一维量子量子上的旋转，我们通过对速度的旋转进行了旋转。 - 沃尔放松是实际上，KPZ动态指数Z = 3/2，KPZ缩放的出现需要整合，而非亚伯SU（2）对称性，我们利用量子气体显微镜的单旋敏感性检测。链计算众所周知，量子多体系统的动力是在淬火后长时间进行的，即使这些复杂的系统则具有水力动力运输特性。在几个不同的普遍性类别中观察到的流体动力学。
The Kardar-Parisi-Zhang (KPZ) universality class describes the coarse-grained behavior of a wealth of classical stochastic models. Surprisingly, KPZ universality was recently conjectured to also describe spin transport in the one-dimensional quantum Heisenberg model. We tested this conjecture by experimentally probing transport in a cold-atom quantum simulator via the relaxation of domain walls in spin chains of up to 50 spins. We found that domain-wall relaxation is indeed governed by the KPZ dynamical exponent z = 3/2 and that the occurrence of KPZ scaling requires both integrability and a nonabelian SU(2) symmetry. Finally, we leveraged the single-spin–sensitive detection enabled by the quantum gas microscope to measure an observable based on spin-transport statistics. Our results yield a clear signature of the nonlinearity that is a hallmark of KPZ universality. Description Hydrodynamics of spin chains Computing the dynamics of quantum many-body systems is notoriously difficult. Nevertheless, at long times after a quench, even these complicated systems are predicted to feature hydrodynamic transport properties. Two groups have used widely tunable and exquisitely controllable atomic systems to study the dynamics of spin propagation in quantum magnetic chains (see the Perspeective by Morningstar and Bakr). Joshi et al. varied the range of interactions in a chain of calcium ions and observed emergent hydrodynamics in several different universality classes. Wei et al. used a quantum gas microscope to monitor spin transport in a Heisenberg chain of cold atoms and found that the system exhibited the so-called Kardar-Parisi-Zhang superdiffusion. —JS Monitoring spin transport reveals anomalous hydrodynamic behavior in quantum magnetic chains.