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Related papers: A unified approach to realize universal quantum ga…

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We present a method of implementing ultrafast two-qubit gates valid for the ultrastrong coupling (USC) and deep strong coupling (DSC) regimes of light-matter interaction, considering state-of-the-art circuit quantum electrodynamics (QED)…

Quantum Physics · Physics 2015-05-30 G. Romero , D. Ballester , Y. M. Wang , V. Scarani , E. Solano

We report the realization of an elementary quantum processor based on a linear crystal of trapped ions. Each ion serves as a quantum bit (qubit) to store the quantum information in long lived electronic states. We present the realization of…

We present a method to enact a deterministic, measurement-free, optically generated controlled-phase gate on two qubits defined by single electrons trapped in large-area quantum dots in a planar microcavity. This method is robust to optical…

Quantum Physics · Physics 2009-10-28 T. D. Ladd , Y. Yamamoto

A goal of quantum information technology is to control the quantum state of a system, including its preparation, manipulation, and measurement. However, scalability to many qubits and controlled connectivity between any selected qubits are…

Superconductivity · Physics 2009-11-10 J. Q. You , J. S. Tsai , Franco Nori

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 propose a scheme to couple two superconducting charge or flux qubits biased at their symmetry points with unequal energy splittings. Modulating the coupling constant between two qubits at the sum or difference of their two frequencies…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. Bertet , C. J. P. M. Harmans , J. E. Mooij

Applications for noisy intermediate-scale quantum computing devices rely on the efficient entanglement of many qubits to reach a potential quantum advantage. Although entanglement is typically generated using two-qubit gates, direct control…

Quantum Physics · Physics 2023-04-18 Niklas J. Glaser , Federico Roy , Stefan Filipp

In order to demonstrate non-trivial quantum computations experimentally, such as the synthesis of arbitrary entangled states, it will be useful to understand how to decompose a desired quantum computation into the shortest possible sequence…

Quantum Physics · Physics 2009-11-10 Farrokh Vatan , Colin Williams

Typical quantum computing schemes require transformations (gates) to be targeted at specific elements (qubits). In many physical systems, direct targeting is difficult to achieve; an alternative is to encode local gates into globally…

Quantum Physics · Physics 2009-10-31 S. C. Benjamin

Universal quantum computation requires the implementation of arbitrary control operations on the quantum register. In most cases, this is achieved by external control fields acting selectively on each qubit to drive single-qubit operations.…

Quantum Physics · Physics 2015-06-19 Jingfu Zhang , Daniel Burgarth , Raymond Laflamme , Dieter Suter

We present a universal set of quantum gate operations based on exchange-only spin qubits in a double quantum dot, where each qubit is obtained by three electrons in the (2,1) filling. Gate operations are addressed by modulating…

Quantum Physics · Physics 2018-09-05 Marco De Michielis , Elena Ferraro , Marco Fanciulli , Enrico Prati

We present a 1D repetition code based on the so-called cat qubits as a viable approach toward hardware-efficient universal and fault-tolerant quantum computation. The cat qubits that are stabilized by a two-photon driven-dissipative…

Quantum Physics · Physics 2019-12-18 Jérémie Guillaud , Mazyar Mirrahimi

The central challenge of quantum computing is implementing high-fidelity quantum gates at scale. However, many existing approaches to qubit control suffer from a scale-performance trade-off, impeding progress towards the creation of useful…

In recent years, the tunable coupling scheme has become the mainstream scheme for designing superconducting quan tum circuits. By working in the dispersive regime, the ZZ coupling and high-energy level leakage can be effectively suppressed…

Quantum Physics · Physics 2024-04-15 Tao Zhang , Chaoying Zhao

Conditional quantum oscillations are investigated for quantum gate operations in superconducting flux qubits. We present an effective Hamiltonian which describes a conditional quantum oscillation in two-qubit systems. Rabi-type quantum…

Quantum Physics · Physics 2015-05-19 Ai Min Chen , Sam Young Cho

We present an explicit construction of a relativistic quantum computing architecture using a variational quantum circuit approach that is shown to allow for universal quantum computing. The variational quantum circuit consists of tunable…

Quantum Physics · Physics 2025-05-19 Philip A. LeMaitre , T. Rick Perche , Marius Krumm , Hans J. Briegel

Despite an apparent progress in implementing individual solid-state qubits, there have been no experimental reports so far on multi-bit gates required for building a real quantum computer. Here we report a new circuit comprising two coupled…

Mesoscale and Nanoscale Physics · Physics 2010-04-20 Yu. A. Pashkin , T. Yamamoto , O. Astafiev , Y. Nakamura , D. V. Averin , J. S. Tsai

We concretely construct an extension of the controlled-U gate in qudit from some elementary gates. We also construct unitary transformation in two-qudit by means of the extended controlled-U gate and show the universality of it.

Quantum Physics · Physics 2007-05-23 Kunio Funahashi

Two of the major obstacles to achieve quantum computing (QC) are (i) scalability to many qubits and (ii) controlled connectivity between any selected qubits. Using Josephson charge qubits, here we propose an experimentally realizable method…

Superconductivity · Physics 2007-05-23 J. Q. You , J. S. Tsai , Franco Nori

Complex control protocols and sensitivity to experimental imperfections have limited the practical implementation of quantum gate operations. Here, we present an analytical framework for universal single-qubit gates using rotational states…

Quantum Physics · Physics 2026-05-06 Qi Chen , Hao-Xuan Luo , Jin-Kang Guo , Qian-Qian Hong , Li-Bao Fan , Chuan-Cun Shu