2023-06-26 米国国立標準技術研究所(NIST)
◆トグルスイッチは接続の強度を調整することができ、ノイズを減少させ、qubitの計算を正確に表示することが可能です。これにより、プログラム可能な量子コンピュータの実現が近づきました。研究チームは、このデバイスをさらに拡張し、より多くのqubitを使用することを計画しています。量子コンピュータの発展により、従来のコンピュータでは解決できなかった問題を解決する可能性があります。
＜関連情報＞
- https://www.nist.gov/news-events/news/2023/06/nist-toggle-switch-can-help-quantum-computers-cut-through-noise
- https://www.nature.com/articles/s41567-023-02107-2
静的に非結合な2量子ビット共振器QEDシステムにおける強力なパラメトリック分散シフト Strong parametric dispersive shifts in a statically decoupled two-qubit cavity QED system
T. Noh,Z. Xiao,X. Y. Jin,K. Cicak,E. Doucet,J. Aumentado,L. C. G. Govia,L. Ranzani,A. Kamal &R. W. Simmonds
Nature Physics Published:26 June 2023
DOI:https://doi.org/10.1038/s41567-023-02107-2
Abstract
Qubits in cavity quantum electrodynamic (QED) architectures are often operated in the dispersive regime, in which the operating frequency of the cavity depends on the energy state of the qubit, and vice versa. The ability to tune these dispersive shifts provides additional options for performing either quantum measurements or logical manipulations. Here we couple two transmon qubits to a lumped-element cavity through a shared superconducting quantum interference device (SQUID). Our design balances the mutual capacitive and inductive circuit components so that both qubits are statically decoupled from the cavity with low flux sensitivity, offering protection from decoherence processes. Parametric driving of the SQUID flux enables independent, dynamical tuning of each qubit’s interaction with the cavity. As a practical demonstration, we perform pulsed parametric dispersive readout of both qubits. The dispersive frequency shifts of the cavity mode follow the theoretically expected magnitude and sign. This parametric approach creates an extensible, tunable cavity QED framework with various future applications, such as entanglement and error correction via multi-qubit parity readout, state and entanglement stabilization, and parametric logical gates.
