The challenge of bridging the terahertz gap with semiconductor lasers faces an inevitable problem of enhanced nonradiative Auger recombination with reduction of photon energy. We show that this problem can be mitigated in mercury–cadmium–telluride quantum wells (HgCdTe QWs), wherein the Auger process is suppressed due to formation of highly symmetric quasi-relativistic electron–hole dispersion imposing strong energy-momentum restrictions on recombining carriers. Such dispersion is formed upon interaction of topological states at the two QW interfaces. We characterize the lasing properties of HgCdTe QWs quantitatively by constructing a microscopic theory for recombination, absorption, and gain and show the feasibility of lasing up to ∼50 μm wavelength at liquid nitrogen temperature with threshold currents two orders of magnitude lower than in existing lasers. Our findings comply with recent experimental data on stimulated far-infrared emission from HgCdTe QWs and show the directions toward achievement of maximum possible lasing wavelength.

中文翻译：

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俄歇抑制HgCdTe量子阱中远红外激光发射的基本限制

用半导体激光器弥合太赫兹间隙的挑战面临着不可避免的问题，即无辐射俄歇复合体的增强和光子能量的减少。我们表明，在汞-镉-碲化物量子阱（HgCdTe QWs）中，可以缓解此问题，其中，由于形成了高度对称的准相对论电子-空穴色散而对重组载流子施加了强烈的能量动量限制，因此俄歇过程得到了抑制。这种分散是在两个QW界面上的拓扑状态相互作用时形成的。我们通过构建用于重组，吸收，吸收和吸收的微观理论来定量表征HgCdTe QW的激光特性。并显示了在液氮温度下以高达50μm的波长发射激光的可行性，其阈值电流比现有激光器低两个数量级。我们的发现符合有关HgCdTe QW激发的远红外发射的最新实验数据，并显示了实现最大可能发射波长的方向。