High-fidelity regimes of resonator-mediated controlled-Z gates between quantum-dot qubits

Fuente: arXiv
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Autores principales: Yang, Guangzhao, Gluza, Marek, Koh, Si Yan, Onggadinata, Kelvin, Wong, Calvin Pei Yu, Goh, Kuan Eng Johnson, Weber, Bent, Ng, Hui Khoon, Koh, Teck Seng
Formato: Preprint
Publicado: 2025
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author Yang, Guangzhao
Gluza, Marek
Koh, Si Yan
Onggadinata, Kelvin
Wong, Calvin Pei Yu
Goh, Kuan Eng Johnson
Weber, Bent
Ng, Hui Khoon
Koh, Teck Seng
author_facet Yang, Guangzhao
Gluza, Marek
Koh, Si Yan
Onggadinata, Kelvin
Wong, Calvin Pei Yu
Goh, Kuan Eng Johnson
Weber, Bent
Ng, Hui Khoon
Koh, Teck Seng
contents Semiconductor double quantum dot (DQD) qubits coupled via superconducting microwave resonators provide a powerful means of long-range manipulation of the qubits' spin and charge degrees of freedom. Quantum gates can be implemented by parametrically driving the qubits while their transition frequencies are detuned from the resonator frequency. Long-range two-qubit controlled-Z (CZ) gates have been proposed for the DQD spin qubit within the rotating-wave approximation (RWA). Rapid gates demand strong coupling, but RWA breaks down when coupling strengths become significant relative to system frequencies. Therefore, understanding the errors arising from approximations used is critical for high-fidelity operation. Here, we go beyond RWA to study CZ gate fidelity for both DQD spin and charge qubits. We propose a novel parametric drive on the charge qubit that produces smaller errors and show that the fidelity of the CZ gate outperforms its spin counterpart, resulting in a much smaller fidelity loss of $0.05\%$ compared to $0.80\%$ for the spin qubit, and greater robustness against qubit dephasing and photon loss. We find that drive amplitude -- a parameter dropped in RWA -- is critical for optimizing fidelity, with the charge qubit exhibiting better tolerance to drive amplitude variations. Our results demonstrate the necessity of going beyond RWA in understanding how long-range gates can be realized in DQD qubits, with charge qubits offering considerable advantages in high-fidelity operation.
format Preprint
id arxiv_https___arxiv_org_abs_2512_00761
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle High-fidelity regimes of resonator-mediated controlled-Z gates between quantum-dot qubits
Yang, Guangzhao
Gluza, Marek
Koh, Si Yan
Onggadinata, Kelvin
Wong, Calvin Pei Yu
Goh, Kuan Eng Johnson
Weber, Bent
Ng, Hui Khoon
Koh, Teck Seng
Mesoscale and Nanoscale Physics
Semiconductor double quantum dot (DQD) qubits coupled via superconducting microwave resonators provide a powerful means of long-range manipulation of the qubits' spin and charge degrees of freedom. Quantum gates can be implemented by parametrically driving the qubits while their transition frequencies are detuned from the resonator frequency. Long-range two-qubit controlled-Z (CZ) gates have been proposed for the DQD spin qubit within the rotating-wave approximation (RWA). Rapid gates demand strong coupling, but RWA breaks down when coupling strengths become significant relative to system frequencies. Therefore, understanding the errors arising from approximations used is critical for high-fidelity operation. Here, we go beyond RWA to study CZ gate fidelity for both DQD spin and charge qubits. We propose a novel parametric drive on the charge qubit that produces smaller errors and show that the fidelity of the CZ gate outperforms its spin counterpart, resulting in a much smaller fidelity loss of $0.05\%$ compared to $0.80\%$ for the spin qubit, and greater robustness against qubit dephasing and photon loss. We find that drive amplitude -- a parameter dropped in RWA -- is critical for optimizing fidelity, with the charge qubit exhibiting better tolerance to drive amplitude variations. Our results demonstrate the necessity of going beyond RWA in understanding how long-range gates can be realized in DQD qubits, with charge qubits offering considerable advantages in high-fidelity operation.
title High-fidelity regimes of resonator-mediated controlled-Z gates between quantum-dot qubits
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2512.00761