We present a blueprint for a maser with a single three-level transmon superconducting artificial atom. The system can be pumped coherently via a two-photon process, and to achieve high population inversion, the relaxation rate of the metastable state is increased via an auxiliary low-$Q$ cavity coupled to a transition between the transmon excited states. We show numerically that such a maser can operate both in the intermediate-coupling regime with super-Poissonian photon statistics and in the strong-coupling regime, where the statistics is sub-Poissonian. For the former the maser exhibits thresholdless behavior, and for the latter there is a well-defined pumping threshold. A useful side effect of the auxiliary resonator is that it allows to overcome the photon blockade effect for the pump, which would otherwise prevent a high photon population. Finally, we observe the bistability of the steady-state Wigner function and the self-quenching effect for some parameters.

中文翻译：

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具有原子反转工程电路的单原子激射器

我们提出了具有单个三能级超环超导人工原子的maser的蓝图。该系统可以通过双光子过程相干地泵浦，并且为了实现高种群反转，可以通过辅助的低能级来提高亚稳态的弛豫率。$问$腔耦合到跨子激发态之间的跃迁。我们从数值上显示，这种激射器既可以在具有超泊松光子统计量的中间耦合体系中运行，也可以在统计量为亚泊松强度的强耦合体系中运行。对于前者，maser表现出无阈值的行为，而对于后者，则有明确定义的泵浦阈值。辅助谐振器的一个有用的副作用是，它可以克服泵的光子阻挡效应，否则该效应会阻止高光子聚集。最后，我们观察了稳态Wigner函数的双稳态和某些参数的自猝灭效应。