论文标题
黑色磷中可调型内的光学电导率和依赖性依赖性的Epsilon-near-Zero行为
Tunable intraband optical conductivity and polarization-dependent epsilon-near-zero behavior in black phosphorus
论文作者
论文摘要
黑磷（BP）为红外和可见光子学提供了相当大的希望。先前已证明，通过对费米水平的调制或应用垂直电场的应用，对带隙和较高的子带进行了有效调整，从而允许对其上述带隙光学特性进行电气控制。在这里，我们通过调节BP中诱导的二维电子气体（2DEG）中的电荷密度来调节带隙（5-15 um）以下的光导率的调节，从而修改其自由载体主导的映射响应。以7x10^12/cm2的中等掺杂密度，我们能够观察到BP的介电介电常数中依赖于极化的Epsilon-Near-Zero行为。如我们的测量所证实的那样，内的偏振灵敏度与两个晶体学方向的有效费米质量的差异密切相关。我们的结果表明，多层BP的潜力允许新兴光子应用的新光学功能。
Black phosphorus (BP) offers considerable promise for infrared and visible photonics. Efficient tuning of the bandgap and higher subbands in BP by modulation of the Fermi level or application of vertical electric fields has been previously demonstrated, allowing electrical control of its above bandgap optical properties. Here, we report modulation of the optical conductivity below the band-gap (5-15 um) by tuning the charge density in a two-dimensional electron gas (2DEG) induced in BP, thereby modifying its free carrier dominated intraband response. With a moderate doping density of 7x10^12/cm2 we were able to observe a polarization dependent epsilon-near-zero behavior in the dielectric permittivity of BP. The intraband polarization sensitivity is intimately linked to the difference in effective fermionic masses along the two crystallographic directions, as confirmed by our measurements. Our results suggest the potential of multilayer BP to allow new optical functions for emerging photonics applications.
