We theoretically study a topological nanospaser, which consists of a silver nanospheroid and MoS₂ monolayer flake of a circular shape. The metal nanospheroid acts as a plasmonic nanoresonator that supports two rotating modes, which are coupled to the corresponding valleys of MoS₂. We apply external circularly polarized light that selectively pumps only one of the valleys of MoS₂. The generated spaser dynamics strongly depends on the size (radius) of the MoS₂ nanoflake. For a small radius, the system has only one spasing regime when only the chirally matched plasmon mode is generated, while at a larger size of MoS₂, depending on the pump intensity, there are two regimes. In one regime, only the chirally matched plasmon mode is generated, while in the other regime both chirally matched and chirally mismatched modes exist. Different regimes of spaser operation also have opposite handedness of the far-field radiated spaser system. Such a topological nanospaser has potential applications in different areas of infrared spectroscopy, sensing, probing, and biomedical treatment.

中文翻译：

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基于TMDC的拓扑Nanospaser：单阈值行为和双阈值行为

从理论上讲，我们研究了一种由纳米银球和圆形MoS ₂单层薄片组成的拓扑纳米SPASER 。金属纳米球体充当等离子体纳米共振器，该等离子体共振器支持两个旋转模式，这两个旋转模式耦合到MoS ₂的相应波谷。我们应用外部圆偏振光，该圆偏振光选择性地仅泵浦MoS _2的一个波谷。生成的Spaser动力学很大程度上取决于MoS ₂纳米薄片的大小（半径）。对于较小的半径，当仅生成手性匹配的等离振子模式时，系统只有一个解构状态，而在较大的MoS ₂大小下，根据泵浦强度，有两种情况。在一种方案中，仅产生手性匹配的等离激元模式，而在另一种方案中，同时存在手性匹配和手性不匹配模式。散打器操作的不同方式也具有远场辐射散打器系统的相反特性。这样的拓扑纳米SPASER在红外光谱，传感，探测和生物医学治疗的不同领域具有潜在的应用。