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Quantum computation provides great speedup over its classical counterpart for certain problems. One of the key challenges for quantum computation is to realize precise control of the quantum system in the presence of noise. Control of the…

Quantum Physics · Physics 2015-11-30 Xing Rong , Jianpei Geng , Fazhan Shi , Ying Liu , Kebiao Xu , Wenchao Ma , Fei Kong , Zhen Jiang , Yang Wu , Jiangfeng Du

Gate fidelity -- an average fidelity over all possible input states -- is the workhorse metric for benchmarking quantum gates or circuits, yet fault-tolerant quantum computing ultimately depends on the worst-case behavior, typically…

Quantum Physics · Physics 2026-03-10 Kyoungho Cho , Ilkwon Sohn , Yongsoo Hwang , Jeongho Bang

High-fidelity manipulation is the key for the physical realization of fault-tolerant quantum computation. Here, we present a protocol to realize universal nonadiabatic geometric gates for silicon-based spin qubits. We find that the…

Quantum Physics · Physics 2020-05-06 Chengxian Zhang , Tao Chen , Sai Li , Xin Wang , Zheng-Yuan Xue

Superconducting transmon qubits are a promising platform for quantum computation, yet they face significant fidelity degradation due to connectivity noise, particularly in the intermediate coupling regime where noise levels are substantial.…

Quantum Physics · Physics 2026-04-29 Quan Fu , Xin Wang , Rui Xiong

We show how a robust high-fidelity universal set of quantum gates can be implemented using a single form of non-adiabatic rapid passage whose parameters are optimized to maximize gate fidelity and reward gate robustness. Each gate in the…

Quantum Physics · Physics 2015-05-27 Ran Li , Frank Gaitan

Fault-tolerant quantum computers which can solve hard problems rely on quantum error correction. One of the most promising error correction codes is the surface code, which requires universal gate fidelities exceeding the error correction…

We characterize the quantum gate fidelity in a state-independent manner by giving an explicit expression for its variance. The method we provide can be extended to calculate all higher order moments of the gate fidelity. Using these results…

Quantum Physics · Physics 2012-04-30 Easwar Magesan , Robin Blume-Kohout , Joseph Emerson

Remarkable experimental advances in quantum computing are exemplified by recent announcements of impressive average gate fidelities exceeding 99.9% for single-qubit gates and 99% for two-qubit gates. Although these high numbers engender…

Quantum Physics · Physics 2015-12-29 Yuval R Sanders , Joel J Wallman , Barry C Sanders

In recent investigations, it has been found that conservation laws generally lead to precision limits on quantum computing. Lower bounds of the error probability have been obtained for various logic operations from the commutation relation…

Quantum Physics · Physics 2009-11-13 Tokishiro Karasawa , Masanao Ozawa

While the accuracy of qubit operations has been greatly improved in the last decade, further development is demanded to achieve the ultimate goal: a fault-tolerant quantum computer that can solve real-world problems more efficiently than…

Quantum Physics · Physics 2024-08-29 Kiyoto Nakamura , Joachim Ankerhold

We use a random search technique to find quantum gate sequences that implement perfect quantum state preparation or unitary operator synthesis with arbitrary targets. This approach is based on the recent discovery that there is a large…

Quantum Physics · Physics 2024-10-25 Sahel Ashhab , Fumiki Yoshihara , Miwako Tsuji , Mitsuhisa Sato , Kouichi Semba

We present a comprehensive analysis of fidelity decay and error accumulation in faulty quantum circuit models. Our work devises an analytical bound for the average fidelity between desired and faulty output states, accounting for errors…

Using geometric phases to realize noise-resilient quantum computing is an important method to enhance the control fidelity. In this work, we experimentally realize a universal nonadiabatic geometric quantum gate set in a superconducting…

High-quality two-qubit gate operations are crucial for scalable quantum information processing. Often, the gate fidelity is compromised when the system becomes more integrated. Therefore, a low-error-rate, easy-to-scale two-qubit gate…

Quantum Physics · Physics 2020-12-24 Yuan Xu , Ji Chu , Jiahao Yuan , Jiawei Qiu , Yuxuan Zhou , Libo Zhang , Xinsheng Tan , Yang Yu , Song Liu , Jian Li , Fei Yan , Dapeng Yu

To generate arbitrary one- and two-qubit gates, the universal decompositions are usually used in quantum computing, and the universality of these decompositions has been demonstrated. However, in realistic experiments, gate errors may…

Quantum Physics · Physics 2022-11-08 Ruixia Wang , Peng Zhao , Haifeng Yu

We demonstrate that conditional as well as unconditional basic operations which are prerequisite for universal quantum gates can be performed with almost 100% fidelity within a strongly interacting two-electron quantum ring. Both sets of…

Mesoscale and Nanoscale Physics · Physics 2016-08-14 Lene Sælen , Erik Waltersson , J. P. Hansen , Eva Lindroth

Realizing the theoretical promise of quantum computers will require overcoming decoherence. Here we demonstrate numerically that high fidelity quantum gates are possible within a framework of quantum dynamical decoupling. Orders of…

Quantum Physics · Physics 2010-12-16 Jacob R. West , Daniel A. Lidar , Bryan H. Fong , Mark F. Gyure

We analyze the performance of quantum teleportation in terms of average fidelity and fidelity deviation. The average fidelity is defined as the average value of the fidelities over all possible input states and the fidelity deviation is…

Quantum Physics · Physics 2018-03-02 Jeongho Bang , Junghee Ryu , Dagomir Kaszlikowski

Recently, several groups have demonstrated two-qubit gate fidelities in semiconductor spin qubit systems above 99%. Achieving this regime of fault-tolerant compatible high fidelities is nontrivial and requires exquisite stability and…