论文标题
在激光驱动的半导体量子孔中，floquet-dirac半学的边缘状态
Edge states of Floquet-Dirac semimetal in a laser-driven semiconductor quantum-well
论文作者
论文摘要
在各种凝结物质系统中观察到的带交叉口被认为是理解低能量的费尔米尼克激发的关键。尽管在这一领域取得了迅速的进展，但对非平衡拓扑状态的探索仍然很少，并且具有提供新平台来创建意外的无质量迪拉克状态的潜在能力。 Here we show that in a semiconductor quantum-well driven by a cw-laser with linear polarization, the optical Stark effect conducts bulk-band crossing, and the resulting Floquet-Dirac semimetallic phase supports an unconventional edge state in the projected one-dimensional Brillouin zone under a boundary condition that an electron is confined in the direction perpendicular to that of the laser polarization.此外，我们揭示了该边缘状态介导了通过调谐激光强度引起的拓扑和非亲笔边缘状态之间的过渡。我们还表明，在不同的边界条件下，边缘状态的特性发生了明显的变化。发现这种差异起源于高度对称点之间的散装布里鲁因区的某个中间区域中存在近四倍的降级点。
Band crossings observed in a wide range of condensed matter systems are recognized as a key to understand low-energy fermionic excitations that behave as massless Dirac particles. Despite rapid progress in this field, the exploration of non-equilibrium topological states remains scarce and it has potential ability of providing a new platform to create unexpected massless Dirac states. Here we show that in a semiconductor quantum-well driven by a cw-laser with linear polarization, the optical Stark effect conducts bulk-band crossing, and the resulting Floquet-Dirac semimetallic phase supports an unconventional edge state in the projected one-dimensional Brillouin zone under a boundary condition that an electron is confined in the direction perpendicular to that of the laser polarization. Further, we reveal that this edge state mediates a transition between topological and non-topological edge states that is caused by tuning the laser intensity. We also show that the properties of the edge states are strikingly changed under a different boundary condition. It is found that such difference originates from that nearly fourfold-degenerate points exist in a certain intermediate region of the bulk Brillouin zone between high-symmetry points.
