_version_ 1866910568346025984
author Marxer, Fabian
Vepsäläinen, Antti
Jolin, Shan W.
Tuorila, Jani
Landra, Alessandro
Ockeloen-Korppi, Caspar
Liu, Wei
Ahonen, Olli
Auer, Adrian
Belzane, Lucien
Bergholm, Ville
Chan, Chun Fai
Chan, Kok Wai
Hiltunen, Tuukka
Hotari, Juho
Hyyppä, Eric
Ikonen, Joni
Janzso, David
Koistinen, Miikka
Kotilahti, Janne
Li, Tianyi
Luus, Jyrgen
Papic, Miha
Partanen, Matti
Räbinä, Jukka
Rosti, Jari
Savytskyi, Mykhailo
Seppälä, Marko
Sevriuk, Vasilii
Takala, Eelis
Tarasinski, Brian
Thapa, Manish J.
Tosto, Francesca
Vorobeva, Natalia
Yu, Liuqi
Tan, Kuan Yen
Hassel, Juha
Möttönen, Mikko
Heinsoo, Johannes
author_facet Marxer, Fabian
Vepsäläinen, Antti
Jolin, Shan W.
Tuorila, Jani
Landra, Alessandro
Ockeloen-Korppi, Caspar
Liu, Wei
Ahonen, Olli
Auer, Adrian
Belzane, Lucien
Bergholm, Ville
Chan, Chun Fai
Chan, Kok Wai
Hiltunen, Tuukka
Hotari, Juho
Hyyppä, Eric
Ikonen, Joni
Janzso, David
Koistinen, Miikka
Kotilahti, Janne
Li, Tianyi
Luus, Jyrgen
Papic, Miha
Partanen, Matti
Räbinä, Jukka
Rosti, Jari
Savytskyi, Mykhailo
Seppälä, Marko
Sevriuk, Vasilii
Takala, Eelis
Tarasinski, Brian
Thapa, Manish J.
Tosto, Francesca
Vorobeva, Natalia
Yu, Liuqi
Tan, Kuan Yen
Hassel, Juha
Möttönen, Mikko
Heinsoo, Johannes
contents Tunable coupling of superconducting qubits has been widely studied due to its importance for isolated gate operations in scalable quantum processor architectures. Here, we demonstrate a tunable qubit-qubit coupler based on a floating transmon device which allows us to place qubits at least 2 mm apart from each other while maintaining over 50 MHz coupling between the coupler and the qubits. In the introduced tunable-coupler design, both the qubit-qubit and the qubit-coupler couplings are mediated by two waveguides instead of relying on direct capacitive couplings between the components, reducing the impact of the qubit-qubit distance on the couplings. This leaves space for each qubit to have an individual readout resonator and a Purcell filter needed for fast high-fidelity readout. In addition, the large qubit-qubit distance reduces unwanted non-nearest neighbor coupling and allows multiple control lines to cross over the structure with minimal crosstalk. Using the proposed flexible and scalable architecture, we demonstrate a controlled-$Z$ gate with $(99.81 \pm 0.02)\%$ fidelity.
format Preprint
id arxiv_https___arxiv_org_abs_2208_09460
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Long-distance transmon coupler with CZ gate fidelity above $99.8\%$
Marxer, Fabian
Vepsäläinen, Antti
Jolin, Shan W.
Tuorila, Jani
Landra, Alessandro
Ockeloen-Korppi, Caspar
Liu, Wei
Ahonen, Olli
Auer, Adrian
Belzane, Lucien
Bergholm, Ville
Chan, Chun Fai
Chan, Kok Wai
Hiltunen, Tuukka
Hotari, Juho
Hyyppä, Eric
Ikonen, Joni
Janzso, David
Koistinen, Miikka
Kotilahti, Janne
Li, Tianyi
Luus, Jyrgen
Papic, Miha
Partanen, Matti
Räbinä, Jukka
Rosti, Jari
Savytskyi, Mykhailo
Seppälä, Marko
Sevriuk, Vasilii
Takala, Eelis
Tarasinski, Brian
Thapa, Manish J.
Tosto, Francesca
Vorobeva, Natalia
Yu, Liuqi
Tan, Kuan Yen
Hassel, Juha
Möttönen, Mikko
Heinsoo, Johannes
Quantum Physics
Tunable coupling of superconducting qubits has been widely studied due to its importance for isolated gate operations in scalable quantum processor architectures. Here, we demonstrate a tunable qubit-qubit coupler based on a floating transmon device which allows us to place qubits at least 2 mm apart from each other while maintaining over 50 MHz coupling between the coupler and the qubits. In the introduced tunable-coupler design, both the qubit-qubit and the qubit-coupler couplings are mediated by two waveguides instead of relying on direct capacitive couplings between the components, reducing the impact of the qubit-qubit distance on the couplings. This leaves space for each qubit to have an individual readout resonator and a Purcell filter needed for fast high-fidelity readout. In addition, the large qubit-qubit distance reduces unwanted non-nearest neighbor coupling and allows multiple control lines to cross over the structure with minimal crosstalk. Using the proposed flexible and scalable architecture, we demonstrate a controlled-$Z$ gate with $(99.81 \pm 0.02)\%$ fidelity.
title Long-distance transmon coupler with CZ gate fidelity above $99.8\%$
topic Quantum Physics
url https://arxiv.org/abs/2208.09460