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In superconducting quantum circuits, decoherence errors in qubits constitute a critical factor limiting quantum gate performance. To mitigate decoherence-induced gate infidelity, rapid implementation of quantum gates is essential. Here we…

We propose a simple scheme for generating a high-fidelity controlled-Z (CZ) gate in a three-component qubit/bus/qubit device. The corresponding tune/detune pulse is single-step, with a near-resonant constant undershoot between the 200 and…

Quantum Physics · Physics 2011-03-25 Andrei Galiautdinov

Contemporary quantum computers encode and process quantum information in binary qubits (d = 2). However, many architectures include higher energy levels that are left as unused computational resources. We demonstrate a superconducting…

Quantum computation requires qubits that can be coupled and realized in a scalable manner, together with universal and high-fidelity one- and two-qubit logic gates \cite{DiVincenzo2000, Loss1998}. Strong effort across several fields have…

We propose the implementation of fast resonant gates in circuit quantum electrodynamics for quantum information processing. We show how a suitable utilization of three-level superconducting qubits inside a resonator constitutes a key tool…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 G. Haack , F. Helmer , M. Mariantoni , F. Marquardt , E. Solano

Continuous gate sets are a key ingredient for near-term quantum algorithms. Here, we demonstrate a hardware-efficient, continuous set of controlled arbitrary-phase ($\mathrm{C}Z_{\theta}$) gates acting on flux-tunable transmon qubits. This…

We propose a simple method to realize a hybrid controlled-controlled-Z (CCZ) gate with two photonic qubits simultaneously controlling a superconducting (SC) target qubit, by employing two microwave cavities coupled to a SC ququart (a…

Quantum Physics · Physics 2023-06-06 Qi-Ping Su , Liang Bin , Yu Zhang , Chui-Ping Yang

Quantum computing using two-dimensional NMR has recently been described using scalar coupling evolution technique [J. Chem. Phys.,109,10603 (1998)]. In the present paper, we describe two-dimensional NMR quantum computing with the help of…

Quantum Physics · Physics 2007-05-23 T. S. Mahesh , Kavita Dorai , Arvind , Anil Kumar

We introduce a new design concept for superconducting quantum bits (qubits) in which we explicitly separate the capacitive element from the Josephson tunnel junction for improved qubit performance. The number of two-level systems (TLS) that…

The performance of a quantum information processor depends on the precise control of phases introduced into the system during quantum gate operations. As the number of operations increases with the complexity of a computation, the phases of…

Quantum Physics · Physics 2014-11-06 I. V. Inlek , G. Vittorini , D. Hucul , C. Crocker , C. Monroe

Superconducting quantum devices are a leading technology for quantum computation, but they suffer from several challenges. Gate errors, coherence errors and a lack of connectivity all contribute to low fidelity results. In particular,…

The native gate set is fundamental to the performance of quantum devices, as it governs the accuracy of basic quantum operations and dictates the complexity of implementing quantum algorithms. Traditional approaches to extending gate sets…

As primitives for entanglement generation, controlled phase gates take a central role in quantum computing. Especially in ideas realizing instances of quantum computation in linear optical gate arrays a closer look can be rewarding. In such…

Quantum Physics · Physics 2015-05-14 K. Kieling , J. L. O'Brien , J. Eisert

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 propose an architecture for a high-fidelity deterministic controlled-phase gate between two photonic qubits using bulk optical nonlinearities in near-term feasible photonic integrated circuits. The gate is enabled by converting…

Quantum Physics · Physics 2020-04-29 Mikkel Heuck , Kurt Jacobs , Dirk R. Englund

We study the implementation of quantum channels with quantum computers while minimizing the experimental cost, measured in terms of the number of Controlled-NOT (C-NOT) gates required (single-qubit gates are free). We consider three…

Quantum Physics · Physics 2017-05-17 Raban Iten , Roger Colbeck , Matthias Christandl

Quantum computation holds the promise of solving computational problems which are believed to be classically intractable. However, in practice, quantum devices are still limited by their relatively short coherence times and imperfect…

Quantum Physics · Physics 2023-12-22 Sagar Silva Pratapsi , Diogo Cruz

Practical Quantum computing hinges on the ability to control large numbers of qubits with high fidelity. Quantum dots define a promising platform due to their compatibility with semiconductor manufacturing. Moreover, high-fidelity…

Mesoscale and Nanoscale Physics · Physics 2023-07-28 W. I. L. Lawrie , M. Rimbach-Russ , F. van Riggelen , N. W. Hendrickx , S. L. de Snoo , A. Sammak , G. Scappucci , J. Helsen , M. Veldhorst

In this paper, we propose a scheme to realize three-qubit controlled phase gate and multiqubit controlled-NOT gate of one qubit simultaneously controlling n target qubit with four level quantum system in a cavity. Adjustment of level…

Quantum Physics · Physics 2015-03-03 Muhammad Waseem , Muhammad Irfan , Shahid Qamar