Wendler Florian, Malic Ermin
Chalmers University of Technology, Department of Applied Physics, SE-412 96 Göteborg, Sweden.
Sci Rep. 2015 Jul 29;5:12646. doi: 10.1038/srep12646.
Terahertz (THz) technology has attracted enormous interest with conceivable applications ranging from basic science to advanced technology. One of the main challenges remains the realization of a well controlled and easily tunable THz source. Here, we predict the occurrence of a long-lived population inversion in Landau-quantized graphene (i.e. graphene in an external magnetic field) suggesting the design of tunable THz Landau level lasers. The unconventional non-equidistant quantization in graphene offers optimal conditions to overcome the counteracting Coulomb- and phonon-assisted scattering channels. In addition to the tunability of the laser frequency, we show that also the polarization of the emitted light can be controlled. Based on our microscopic insights into the underlying many-particle mechanisms, we propose two different experimentally realizable schemes to design tunable graphene-based THz Landau level lasers.
太赫兹（THz）技术因其从基础科学到先进技术等诸多潜在应用而备受关注。主要挑战之一仍是实现一个可控且易于调谐的太赫兹源。在此，我们预测在朗道量子化石墨烯（即在外部磁场中的石墨烯）中会出现长寿命粒子数反转，这表明可设计出可调谐的太赫兹朗道能级激光器。石墨烯中非常规的非等距量子化提供了最佳条件，以克服相互抵消的库仑散射和声子辅助散射通道。除了激光频率的可调性外，我们还表明发射光的偏振也可控制。基于我们对潜在多粒子机制的微观洞察，我们提出了两种不同的、可通过实验实现的方案来设计基于石墨烯的可调谐太赫兹朗道能级激光器。
