论文标题
具有噪声不敏感的等离子水平和受衰减保护的浮雕状态的超导量子
A superconducting qubit with noise-insensitive plasmon levels and decay-protected fluxon states
论文作者
论文摘要
电感分流的转基因（IST）是具有指数抑制的Fluxon跃迁的超导量子，和近似于Transmon的频谱。它与Transmon具有许多特征，但对所有级别的充电偏移不敏感，并通过二次通量噪声抑制了精确的通量可调节性。在这项工作中，我们提出并意识到在Transmon限制中深处的IST量子位，其中大几何感应仅仅是扰动。磁通量仅为5.1 MHz，我们到达了鱿鱼装置的“甜点无处不在”，在完整的通量量子上具有稳定的连贯性时间。靠近通量退化点，设备揭示了两个准排优化基态之间的隧穿物理，在几分钟内典型观察到的寿命。将来，可以使用这种Qubit制度来避免在高功率读出或驱动的玻色量量子量子量子的情况下泄漏到无限制的Transmon状态。此外，在单个设备中，可控制的等离子体转变与稳定的磁通状态的结合可能为改进量子量编码方案提供了前进的方向。
The inductively shunted transmon (IST) is a superconducting qubit with exponentially suppressed fluxon transitions and a plasmon spectrum approximating that of the transmon. It shares many characteristics with the transmon but offers charge offset insensitivity for all levels and precise flux tunability with quadratic flux noise suppression. In this work we propose and realize IST qubits deep in the transmon limit where the large geometric inductance acts as a mere perturbation. With a flux dispersion of only 5.1 MHz we reach the 'sweet-spot everywhere' regime of a SQUID device with a stable coherence time over a full flux quantum. Close to the flux degeneracy point the device reveals tunneling physics between the two quasi-degenerate ground states with typical observed lifetimes on the order of minutes. In the future, this qubit regime could be used to avoid leakage to unconfined transmon states in high-power read-out or driven-dissipative bosonic qubit realizations. Moreover, the combination of well controllable plasmon transitions together with stable fluxon states in a single device might offer a way forward towards improved qubit encoding schemes.
