Seeing beyond the light: Vison and photon electrodynamics in quantum spin ice
Seeing beyond the light: Vison and photon electrodynamics in quantum spin ice
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DOI：
10.1103/physrevb.100.014417
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发表时间：
2019-02
影响因子：
3.7
通讯作者：
A. Szab'o;C. Castelnovo
中科院分区：
文献类型：
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作者：
A. Szab'o;C. Castelnovo
了解量子自旋液体中激发的性质和行为，以及一般物质的拓扑相，对于候选材料的实验检测和表征是至关重要的。然而，目前的理论和数值技术能力有限，特别是在研究有间隙的激发时。在这里，我们提出了一种半经典数值方法来研究其自旋液体行为由微扰环交换哈密顿量支撑的系统。我们的方法可以很容易地获得热力学和光谱性质。我们特别关注量子自旋冰及其光子和粘子激发。在将该方法与现有的光子结果进行基准比较后，我们使用它来表征粘子及其热力学行为，这在很大程度上到目前为止还没有被探索过。我们发现，与经典自旋冰中的自旋相比，粘子形成了一种弱电解液：在低温下，粘子对是主要的粒子。这反映在热力学参数的行为上，例如相关关联器中的夹点主题。粘子似乎也与光子背景强烈杂化，这一现象影响了这些准粒子在非弹性响应测量中的表现方式。我们的结果表明，这种方法及其推广可以很大程度上帮助我们理解准粒子及其在量子自旋冰和其他量子自旋液体、量子二聚体模型和一般晶格规范理论中的相互作用。
Understanding the nature and behavior of excitations in quantum spin liquids, and in topological phases of matter in general, is of fundamental importance and has proven crucial for experimental detection and characterization of candidate materials. Current theoretical and numerical techniques, however, have limited capabilities, especially when it comes to studying gapped excitations. Here, we propose a semiclassical numerical method to study systems whose spin liquid behavior is underpinned by perturbative ring-exchange Hamiltonians. Our method can readily access both thermodynamic and spectral properties. We focus in particular on quantum spin ice and its photon and vison excitations. After benchmarking the method against existing results on photons, we use it to characterize visons and their thermodynamic behavior, which remained hitherto largely unexplored. We find that visons, in contrast to spinons in classical spin ice, form a weak electrolyte: Vison pairs are the dominant population at low temperatures. This is reflected in the behavior of thermodynamic quantities, such as pinch point motifs in the relevant correlators. Visons also appear to strongly hybridize with the photon background, a phenomenon that affects the way these quasiparticles may show up in inelastic response measurements. Our results demonstrate that the method, and generalizations thereof, can substantially help our understanding of quasiparticles and their interplay in quantum spin ice and other quantum spin liquids, quantum dimer models, and lattice gauge theories in general.