论文标题
快速参数两数Q Q Qubit Gate，用于使用双传输的固定频率超导量子台
Fast parametric two-qubit gate for highly detuned fixed-frequency superconducting qubits using a double-transmon coupler
论文作者
论文摘要
已经报道了高性能的两分门，通过单跨型耦合器（STC）结合了超导码头。它们中的大多数是针对量子台进行的，因为STC减少了剩余的$ ZZ $耦合，因此STC的剩余$ zz $耦合是具有挑战性的。但是，就频率拥挤和串扰而言，高度失调的Qubits是可取的。在这里，我们使用最近建议的可调式耦合器（称为双传输型纤维耦合器（DTC））来证明高性能参数门的高性能参数门。应用交流通量脉冲，我们可以执行最大纠缠的通用门（$ \ sqrt {\ rm iswap} $），其平均保真度超过99.99 $ \％$，而短门时间约为24 ns。这种速度可与基于共振的大门相当，用于略有引人注目的可调量子。此外，使用直流通量脉冲，我们可以实现另一种称为CZ门的纠缠门，平均保真度超过99.99 $ \％$，而门的时间约为18 ns。鉴于易碎性和可行设置，我们可以预期DTC将在不久的将来实现高性能量子计算机。
High-performance two-qubit gates have been reported with superconducting qubits coupled via a single-transmon coupler (STC). Most of them are implemented for qubits with a small detuning since reducing residual $ZZ$ coupling for highly detuned qubits by an STC is challenging. In terms of the frequency crowding and crosstalk, however, highly detuned qubits are desirable. Here, we numerically demonstrate a high-performance parametric gate for highly detuned fixed-frequency qubits using a recently proposed tunable coupler called a double-transmon coupler (DTC). Applying an ac flux pulse, we can perform a maximally entangling universal gate ($\sqrt{\rm iSWAP}$) with an average fidelity over 99.99$\%$ and a short gate time of about 24 ns. This speed is comparable to resonance-based gates for slightly detuned tunable qubits. Moreover, using a dc flux pulse alternatively, we can achieve another kind of entangling gate called a CZ gate with an average fidelity over 99.99$\%$ and a gate time of about 18 ns. Given the frexibility and feasible settings, we can expect that the DTC will contribute to realizing a high-performance quantum computer in the near future.
