Applying electric and magnetic field bias in a 3D superconducting waveguide cavity with high quality factor
Applying electric and magnetic field bias in a 3D superconducting waveguide cavity with high quality factor
复制标题
在高品质因数的 3D 超导波导腔中施加电场和磁场偏置
DOI：
10.1088/2058-9565/aad362
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发表时间：
2017
影响因子：
6.7
通讯作者：
A. Wallraff
中科院分区：
文献类型：
--
作者：
M. Stammeier;S. Garcia;A. Wallraff
三维微波波导腔是许多腔量子电动力学实验的重要工具。然而，控制腔内具有直流磁场的量子发射器的需要通常将此类实验限制在品质因数相对较低（约 104）的常导腔中。同样，迄今为止，在常导和超导波导腔中控制具有直流电场的量子发射器一直很困难，因为直流电极的插入强烈限制了品质因数。在这里，我们提出了一种在超导波导腔内施加直流电场的方法，该方法基于在微波电场的节点处插入直流电极。此外，我们提出了一种通过将磁通量捕获在位于腔体相对壁上的孔中来在同一腔体中施加直流磁场的方法。我们证明了这种由铌制成的超导矩形腔的 TE301 模式在少数光子能级和 3 K 的基础温度下保持了 Q int ≃ 1.7 × 10 6 的高内部品质因数。与腔的微波电场耦合的里德伯原子云用于分别通过二次斯塔克效应和塞曼效应探测所施加的直流电场和磁场。
Three-dimensional microwave waveguide cavities are essential tools for many cavity quantum electrodynamics experiments. However, the need to control quantum emitters with dc magnetic fields inside the cavity often limits such experiments to normal-conducting cavities with relatively low quality factors of about 104. Similarly, controlling quantum emitters with dc electric fields in normal- and superconducting waveguide cavities has so far been difficult, because the insertion of dc electrodes has strongly limited the quality factor. Here, we present a method to apply dc electric fields within a superconducting waveguide cavity, which is based on the insertion of dc electrodes at the nodes of the microwave electric field. Moreover, we present a method to apply dc magnetic fields within the same cavity by trapping the magnetic flux in holes positioned in facing walls of the cavity. We demonstrate that the TE301 mode of such a superconducting, rectangular cavity made from niobium maintains a high internal quality factor of Q int ≃ 1.7 × 10 6 at the few photon level and a base temperature of 3 K. A cloud of Rydberg atoms coupled to the microwave electric field of the cavity is used to probe the applied dc electric and magnetic fields via the quadratic Stark effect and the Zeeman effect, respectively.