aqora

Engineering Qubit-Qubit Interactions in Circuit QED Lattices

Alicia J. Kollár

Bulletin of the American Physical SocietyMar 19, 20210 citations

Suppression of Unwanted Z Z Interactions in a Hybrid Two-Qubit System

Jaseung Ku, Xuexin Xu, Markus Brink +4 more

Mitigating crosstalk errors, whether classical or quantum mechanical, is critically important for achieving high-fidelity entangling gates in multiqubit circuits. For weakly anharmonic superconducting qubits, unwanted ZZ interactions can be suppressed by combining qubits with opposite anharmonicity. We present experimental measurements and theoretical modeling of two-qubit gate error for gates based on the cross resonance interaction between a capacitively shunted flux qubit and a transmon, and demonstrate the elimination of the ZZ interaction.Mitigating crosstalk errors, whether classical or quantum mechanical, is critically important for achieving high-fidelity entangling gates in multiqubit circuits. For weakly anharmonic superconducting qubits, unwanted ZZ interactions can be suppressed by combining qubits with opposite anharmonicity. We present experimental measurements and theoretical modeling of two-qubit gate error for gates based on the cross resonance interaction between a capacitively shunted flux qubit and a transmon, and demonstrate the elimination of the ZZ interaction.

arXiv:2003.02775Physical Review LettersNov 11, 2020111 citations

Generating a Two-Qubit Entanglement State in Cavity QED

Fujun Zhang, Dongxin Wang, Kun Liu +1 more

International Journal of Theoretical PhysicsDec 15, 20143 citations

Parasitic-free gate: A protected switch between idle and entangled states

Xuexin Xu, M. H. Ansari

We propose a gate to switch superconducting qubit pairs in and out of a two-body interaction. This gate uses cross resonance driving on a tunable circuit with adjusted parameters and without accumulating residual ZZ interaction for idle and interacting qubits. It is imperative that this gate does not spread errors through the quantum register. Our detailed theoretical results show that these error-free modes do not necessarily require largely tunable circuits, such as magnetic modulation of qubits or couplers. We obtain the operational gate on weakly tuneable circuits as well and show that switching between them is remarkably fast.We propose a gate to switch superconducting qubit pairs in and out of a two-body interaction. This gate uses cross resonance driving on a tunable circuit with adjusted parameters and without accumulating residual ZZ interaction for idle and interacting qubits. It is imperative that this gate does not spread errors through the quantum register. Our detailed theoretical results show that these error-free modes do not necessarily require largely tunable circuits, such as magnetic modulation of qubits or couplers. We obtain the operational gate on weakly tuneable circuits as well and show that switching between them is remarkably fast.

arXiv:2202.05208Feb 10, 20220 citations

Methods for entanglement in circuit QED

Felix Motzoi, Mohan Sarovar, Michael H. Goerz +2 more

Bulletin of the American Physical SocietyMar 21, 20130 citations

Efficient Entanglement Generation of Two Superconducting Qubits in a Circuit QED

Run‐Ying Yan, Zhi‐Bo Feng

Abstract The optimal generation of entangled states is of significance to information processing and state engineering. Here, an efficient scheme is proposed for creating entangled states between two superconducting qubits in a circuit quantum electrodynamics (QED). The two qubits that resonantly interact with a common cavity mode of transmission‐line resonator (TLR) can be effectively coupled by the data bus of the microwave resonator. By the invariant‐based shortcuts to adiabaticity (STA), two types of maximally entangled states can be controllably induced only by adjusting the Rabi drivings. Based on the resonant drivings with constant rates, the shortcut strategy is capable of implementing faster operations when compared with the dispersive approach. The fidelities are highly robust against the decoherence effects and the instabilities of Rabi rates. Thus the proposal could offer a potential route toward the entanglement generations in an optimized manner.Abstract The optimal generation of entangled states is of significance to information processing and state engineering. Here, an efficient scheme is proposed for creating entangled states between two superconducting qubits in a circuit quantum electrodynamics (QED). The two qubits that resonantly interact with a common cavity mode of transmission‐line resonator (TLR) can be effectively coupled by the data bus of the microwave resonator. By the invariant‐based shortcuts to adiabaticity (STA), two types of maximally entangled states can be controllably induced only by adjusting the Rabi drivings. Based on the resonant drivings with constant rates, the shortcut strategy is capable of implementing faster operations when compared with the dispersive approach. The fidelities are highly robust against the decoherence effects and the instabilities of Rabi rates. Thus the proposal could offer a potential route toward the entanglement generations in an optimized manner.

Annalen der PhysikJun 13, 20252 citations

Driving two-qubit entanglement with an enhanced ZZ interaction in circuit QED

Related papers

Driving two-qubit entanglement with an enhanced ZZ interaction in circuit QED

Related papers