论文标题
从安德森塔(Anderson Towers)重建古典天空:Quantum darwinism
Reconstruction of classical skyrmions from Anderson towers: quantum Darwinism in action
论文作者
论文摘要
量子Skyrmion概念的开发旨在扩大基本研究的范围和对经典拓扑拓扑保护的磁纹理的实际应用,并有可能为创建新的量子技术铺平道路。毫无疑问,这要求建立经典的天空与其量子对应物之间建立连接:Skyrmion Wave函数是一种本质上比代表经典Skyrmion的经典旋转的非分线性配置更复杂的对象。最新的是,这种量子古典关系仅在不同的物理观察物的水平上建立,而不是在经典和量子状态本身。在这项工作中,我们表明,只能使用相应的量子自旋型汉密尔顿的光谱中的低能部分重建经典的Skyrmion自旋顺序。这可以通过对安德森(Anderson)对状态塔(TOS)的概念的柔性无对称的数值实现来完成,该想法允许人们研究已知的以及未知的经典旋转配置,并可以正确选择损失函数。我们表明,TOS在量子系统范围中的存在并不能先验地确保可以作为实际测量结果获得经典的Skyrmion磁化特征。由于与环境的相互作用,应通过适当的反应机制来补充此过程。后来选择在测量前选择TOS本征函数的特定组合,因此确保了从高度输入的量子源性状态到经典的非结合磁序的过渡,该磁性在实际实验中测量。在天空中获得的结果使我们能够重新考虑量子抗铁磁性的问题。
The development of the quantum skyrmion concept is aimed at expanding the scope of the fundamental research and practical applications for classical topologically-protected magnetic textures, and potentially paves the way for creating new quantum technologies. Undoubtedly, this calls for establishing a connection between a classical skyrmion and its quantum counterpart: a skyrmion wave function is an intrinsically more complex object than a non-collinear configuration of classical spins representing the classical skyrmion. Up to date, such a quantum-classical relation was only established on the level of different physical observables, but not for classical and quantum states per se. In this work, we show that the classical skyrmion spin order can be reconstructed using only the low-energy part of the spectrum of the corresponding quantum spin Hamiltonian. This can be done by means of a flexible symmetry-free numerical realization of Anderson's idea of the towers of states (TOS) that allows one to study known, as well as unknown, classical spin configurations with a proper choice of the loss function. We show that the existence of the TOS in the spectrum of the quantum systems does not guarantee a priori that the classical skyrmion magnetization profile can be obtained as an outcome of the actual measurement. This procedure should be complemented by a proper decoherence mechanism due to the interaction with the environment. The later selects a specific combination of the TOS eigenfunctions before the measurement and, thus, ensures the transition from a highly-entangled quantum skyrmionic state to a classical non-collinear magnetic order that is measured in real experiments. The results obtained in the context of skyrmions allow us to take a fresh look at the problem of quantum antiferromagnetism.