论文标题
电磁辐射下具有平坦波段的Dirac Hamiltonians的电子过渡及其应用于$α-\ Mathcal {t} _3 $ Graphene模型
Electron transitions for Dirac Hamiltonians with flat-bands under electromagnetic radiation and its application to the $α-\mathcal{T}_3$ graphene model
论文作者
论文摘要
在具有狄拉克状线性分散体的系统中，总是有状态符合任意频率$ω$的电磁辐射的共振条件。当存在平坦的频带时，发现两种共鸣过渡。考虑到$α-\ Mathcal {t} _3 $石墨烯模型是具有平坦带和狄拉克锥的最小模型，并使用交互作用图来描述动力学，我们研究了由外部电磁场引起的频段转变。我们发现过渡取决于电子动量和电磁场波矢量之间的相对角。对于并行的发生率，使用浮雕理论发现过渡，而对于其他角度扰动理论。在所有情况下，都会发现过渡概率和频率。对于参数$α$或通过电荷掺杂的某些特殊值，该系统的表现为三个级别或两个级别的Rabi系统。将所有这些先前的结果与数值模拟进行了比较。两者之间都发现了一个很好的协议。获得的结果对于提供系统的量子控制很有用。
In a system with a Dirac-like linear dispersion there are always states that fulfill the resonance condition for electromagnetic radiation of arbitrary frequency $Ω$. When a flat band is present two kinds of resonant transitions are found. Considering the $α-\mathcal{T}_3$ graphene model as a minimal model with a flat band and Dirac cones, and describing the dynamics using the interaction picture, we study the band transitions induced by an external electromagnetic field. We found that transitions depend upon the relative angle between the electron momentum and the electromagnetic field wave vector. For parallel incidence, the transitions are found using Floquet theory while for other angles perturbation theory is used. In all cases, the transition probabilities and the frequencies are found. For some special values of the parameter $α$ or by charge doping, the system behaves as a three level or a two-level Rabi system. All these previous results were compared with numerical simulations. A good agreement was found between both. The obtained results are useful to provide a quantum control of the system.
