Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-strasse 1, 85748 Garching, Germany.
Instituto de Física Fundamental, IFF-CSIC, Serrano 113-bis, Madrid E-28006, Spain.
Phys Rev Lett. 2014 Nov 7;113(19):193601. doi: 10.1103/PhysRevLett.113.193601.
We show how a pair of superconducting qubits coupled to a microwave cavity mode can be used to engineer a single-atom laser that emits light into a nonclassical state. Our scheme relies on the dressing of the qubit-field coupling by periodic modulations of the qubit energy. In the dressed basis, the radiative decay of the first qubit becomes an effective incoherent pumping mechanism that injects energy into the system, hence turning dissipation to our advantage. A second, auxiliary qubit is used to shape the decay within the cavity, in such a way that lasing occurs in a squeezed basis of the cavity mode. We characterize the system both by mean-field theory and exact calculations. Our work may find applications in the generation of squeezing and entanglement in circuit QED, as well as in the study of dissipative few- and many-body phase transitions.
我们展示了如何使用一对超导量子比特耦合到微波腔模式，来设计一种单原子激光，使其发射进入非经典状态的光。我们的方案依赖于通过周期性调制量子比特能量来修饰量子比特-场耦合。在修饰后的基中，第一个量子比特的辐射衰变成为一种有效的非相干泵浦机制，将能量注入系统，从而将耗散转化为我们的优势。第二个辅助量子比特用于在腔中塑造衰变，从而使激光在腔模的压缩基中发生。我们通过平均场理论和精确计算来描述系统。我们的工作可能会在电路 QED 中产生压缩和纠缠，以及在研究耗散少体和多体相变方面找到应用。
