Implementation of Conditional-Phase Gates based on tunable ZZ-Interactions

• URL: http://arxiv.org/abs/2005.08863v1
• Date: Mon, 18 May 2020 16:37:32 GMT
• Title: Implementation of Conditional-Phase Gates based on tunable ZZ-Interactions
• Authors: Michele C. Collodo, Johannes Herrmann, Nathan Lacroix, Christian Kraglund Andersen, Ants Remm, Stefania Lazar, Jean-Claude Besse, Theo Walter, Andreas Wallraff, Christopher Eichler
• Abstract summary: In superconducting circuits two-qubit gates are typically based either on RF-controlled interactions or on the in-situ tunability of qubitbility. We present an alternative approach using a tunable cross-Kerr-type ZZ-interaction between two qubits, which we realize by a flux-tunable coupler. We control the ZZ-coupling rate over three orders of magnitude to perform a rapid element (38 ns), high-contrast, low leakage (0.14 conditional-phase CZ gate with a fidelity of 97.9 % without relying on the resonant interaction with a non-computational state
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: High fidelity two-qubit gates exhibiting low crosstalk are essential building blocks for gate-based quantum information processing. In superconducting circuits two-qubit gates are typically based either on RF-controlled interactions or on the in-situ tunability of qubit frequencies. Here, we present an alternative approach using a tunable cross-Kerr-type ZZ-interaction between two qubits, which we realize by a flux-tunable coupler element. We control the ZZ-coupling rate over three orders of magnitude to perform a rapid (38 ns), high-contrast, low leakage (0.14 %) conditional-phase CZ gate with a fidelity of 97.9 % without relying on the resonant interaction with a non-computational state. Furthermore, by exploiting the direct nature of the ZZ-coupling, we easily access the entire conditional-phase gate family by adjusting only a single control parameter.

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