English
Related papers

Related papers: Minimal-Energy Optimal Control of Tunable Two-Qubi…

200 papers

Dynamical decoupling (DD) is a key technique for suppressing decoherence and preserving the performance of quantum algorithms. We introduce a measurement-based DD (MDD) protocol that determines control unitary gates from partial…

Quantum Physics · Physics 2025-11-18 Jeongwoo Jae , Changwon Lee , Juzar Thingna , Yeong-Dae Kwon , Daniel K. Park

The possibility to utilize different types of two-qubit gates on a single quantum computing platform adds flexibility in the decomposition of quantum algorithms. A larger hardware-native gate set may decrease the number of required gates,…

We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's…

Striving for higher gate fidelity is crucial not only for enhancing existing noisy intermediate-scale quantum (NISQ) devices but also for unleashing the potential of fault-tolerant quantum computation through quantum error correction. A…

Quantum Physics · Physics 2024-11-27 Rui Li , Kentaro Kubo , Yinghao Ho , Zhiguang Yan , Yasunobu Nakamura , Hayato Goto

High-fidelity single- and two-qubit gates are essential building blocks for a fault-tolerant quantum computer. While there has been much progress in suppressing single-qubit gate errors in superconducting qubit systems, two-qubit gates…

The design of coupler-based superconducting two-qubit gates simplifies circuit layout and alleviate frequency crowding, thereby enhancing the scalability and flexibility of quantum chips. However, in such architectures, a trade-off often…

Quantum Physics · Physics 2026-04-13 Bo-Xun Deng , Jia-Qi Hu , Cheng-Yun Ding , Zheng-Yuan Xue , Tao Chen

We demonstrate a robust quantum control framework that enables high-fidelity gate operations in semiconductor spin qubit systems with always-on couplings. Always-on interactions between qubits pose a fundamental challenge for quantum…

Quantum Physics · Physics 2025-03-18 Yong-Ju Hai , Shihang Zhang , Haoyu Guan , Peihao Huang , Yu He , Xiu-Hao Deng

Hybrid systems comprising superconducting and semiconducting materials are promising architectures for quantum computing. Superconductors induce long-range interactions between the spin degrees of freedom of semiconducting quantum dots.…

Quantum Physics · Physics 2024-02-16 Maria Spethmann , Stefano Bosco , Andrea Hofmann , Jelena Klinovaja , Daniel Loss

The ability to engineer high-fidelity gates on quantum processors in the presence of systematic errors remains the primary barrier to achieving quantum advantage. Quantum optimal control methods have proven effective in experimentally…

Quantum Physics · Physics 2021-03-30 Thomas Propson , Brian E. Jackson , Jens Koch , Zachary Manchester , David I. Schuster

Electron spin qubits in silicon are a promising platform for fault-tolerant quantum computing. Low-frequency noise, including nuclear spin fluctuations and charge noise, is a primary factor limiting gate fidelities. Suppressing this noise…

Mesoscale and Nanoscale Physics · Physics 2024-11-13 Ning Wang , Shao-Min Wang , Run-Ze Zhang , Jia-Min Kang , Wen-Long Lu , Hai-Ou Li , Gang Cao , Bao-Chuan Wang , Guo-Ping Guo

Superconducting protected qubits aim to achieve sufficiently low error rates so as to allow realization of error-corrected, utility-scale quantum computers. A recent proposal encodes a protected qubit in the quasicharge degree of freedom of…

Quantum Physics · Physics 2026-01-09 Nicholas M. Christopher , Deniz E. Stiegemann , Abhijeet Alase , Thomas M. Stace

Established methods for dissipative state preparation typically rely on resolving resonances, limiting the target state fidelity due to competition between the stabilization mechanism and uncontrolled dissipation. We propose a protocol…

Quantum Physics · Physics 2020-06-30 E. Doucet , F. Reiter , L. Ranzani , A. Kamal

Modular multilevel converters (MMC) and cascaded H-bridge (CHB) converters are an established concept in ultra-high voltage systems. In combination with batteries, these circuits allow dynamically changing the series or parallel…

Systems and Control · Electrical Eng. & Systems 2024-10-28 N. Tashakor , J. Kacetl , J. Fang , Z. Li , S. Goetz

A field configuration utilizing local static and oscillating fields is constructed to achieve universal (but low-order) protection of two-qubit states. That is, two-qubit states can be protected against arbitrary system-environment coupling…

Quantum Physics · Physics 2012-01-20 Adam Zaman Chaudhry , Jiangbin Gong

We present a superconducting qubit which consists of two strongly coupled modes: one for data storage and one for coupling, allowing faster, higher-fidelity entangling gates and readout. The use of a dedicated coupling mode allows nonlinear…

Quantum Physics · Physics 2025-06-06 Jeremy B. Kline , Alec Yen , Stanley Chen , Kevin P. O'Brien

We demonstrate high fidelity entangling quantum gates within a chain of five trapped ion qubits by optimally shaping optical fields that couple to multiple collective modes of motion. We individually address qubits with segmented optical…

Quantum Physics · Physics 2014-05-20 T. Choi , S. Debnath , T. A. Manning , C. Figgatt , Z. -X. Gong , L. -M. Duan , C. Monroe

The continuous-variable controlled-Z gate is a canonical two-mode gate for universal continuous-variable quantum computation. It is considered as one of the most fundamental continuous-variable quantum gates. Here we present a scheme for…

Quantum Physics · Physics 2015-05-27 Ming-Feng Wang , Nian-Quan Jiang , Qing-Li Jin , Yi-Zhuang Zheng

Achieving fast and high-fidelity qubit operations is crucial for unlocking the potential of quantum computers. In particular, reaching low gate errors in two-qubit gates has been a long-standing challenge in the field of superconducting…

Realistic multi-qubit noise processes often result in error mechanisms that are not captured by the probabilistic, Markovian error models commonly employed in circuit-level analyses of quantum fault-tolerance. By working within an…

The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit…