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Related papers: High-fidelity CNOT gate for spin qubits with asymm…

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Quantum computation requires the precise control of the evolution of a quantum system, typically through application of discrete quantum logic gates on a set of qubits. Here, we use the cross-resonance interaction to implement a gate…

We apply the methodology of optimal control theory to the problem of implementing quantum gates in continuous variable systems with quadratic Hamiltonians. We demonstrate that it is possible to define a fidelity measure for continuous…

Quantum Physics · Physics 2009-11-13 Rebing Wu , Raj Chakrabarti , Herschel Rabitz

Efficient implementation of quantum algorithms requires single- or multi-qubit gates with high fidelity. In this report, we report that the fidelity of single-qubit gate operations on open quantum systems has a maximum value corresponding…

Quantum Physics · Physics 2020-04-29 Nilanjana Chanda , Rangeet Bhattacharyya

In recent years qubit designs such as transmons approached the fidelities of up to 0.999. However, even these devices are still insufficient for realizing quantum error correction requiring better than 0.9999 fidelity. Topologically…

Quantum Physics · Physics 2021-10-13 Andrey R. Klots , Lev B. Ioffe

Hole spin qubits in semiconductor quantum dots (QDs) are promising candidates for quantum information processing due to their weak hyperfine coupling to nuclear spins, and to the strong spin-orbit coupling which allows for rapid operation…

Mesoscale and Nanoscale Physics · Physics 2022-12-02 D. Fernandez-Fernandez , Y. Ban , G. Platero

Native multi-qubit parity gates have various potential quantum computing applications, such as entanglement creation, logical state encoding and parity measurement in quantum error correction. Here, using simultaneous cross-resonance drives…

Quantum Physics · Physics 2023-10-06 Toshinari Itoko , Moein Malekakhlagh , Naoki Kanazawa , Maika Takita

We present the first demonstration of a CNOT gate using neutral atoms. Our implementation of the CNOT uses Rydberg blockade interactions between neutral atoms held in optical traps separated by >8 \mu\rm m. We measure CNOT fidelities of…

Quantum Physics · Physics 2011-07-19 L. Isenhower , E. Urban , X. L. Zhang , A. T. Gill , T. Henage , T. A. Johnson , T. G. Walker , M. Saffman

Single-qubit gates are essential components of a universal quantum computer. Without selective addressing of individual qubits, scalable implementation of quantum algorithms is not possible. When the qubits are discrete points or regions on…

Long coherence times, large anharmonicity and robust charge-noise insensitivity render fluxonium qubits an interesting alternative to transmons. Recent experiments have demonstrated record coherence times for low-frequency fluxonia. Here,…

Quantum Physics · Physics 2023-01-04 D. K. Weiss , Helin Zhang , Chunyang Ding , Yuwei Ma , David I. Schuster , Jens Koch

While mapping a quantum circuit to the physical layer one has to consider the numerous constraints imposed by the underlying hardware architecture. Connectivity of the physical qubits is one such constraint that restricts two-qubit…

Quantum Physics · Physics 2022-11-14 Vlad Gheorghiu , Jiaxin Huang , Sarah Meng Li , Michele Mosca , Priyanka Mukhopadhyay

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…

We analyse non-adiabatic non-Abelian holonomic transformations of spin-qubits confined to a linear time dependent harmonic trap with time dependent Rashba interaction. For this system exact results can be derived for spin rotation angle…

Mesoscale and Nanoscale Physics · Physics 2019-12-03 Lara Ulcakar , Anton Ramsak

The spin states of single electrons in gate-defined quantum dots satisfy crucial requirements for a practical quantum computer. These include extremely long coherence times, high-fidelity quantum operation, and the ability to shuttle…

The performance requirements for fault-tolerant quantum computing are very stringent. Qubits must be manipulated, coupled, and measured with error rates well below 1%. For semiconductor implementations, silicon quantum dot spin qubits have…

Confined electron spins are preferred candidates for embodying quantum information in the solid state. A popular idea is the use of optical excitation to achieve the ``best of both worlds'', i.e. marrying the long spin decoherence times…

Quantum Physics · Physics 2009-11-13 Erik M. Gauger , Simon C. Benjamin , Ahsan Nazir , Brendon W. Lovett

The accurate implementation of quantum gates is essential for the realisation of quantum algorithms and digital quantum simulations. This accuracy may be increased on noisy hardware through the variational optimisation of gates, however the…

Quantum Physics · Physics 2021-07-14 Sean Greenaway , Frédéric Sauvage , Kiran E. Khosla , Florian Mintert

The spin of an electron confined in semiconductor quantum dots is currently a promising candidate for quantum bit (qubit) implementations. Taking advantage of existing CMOS integration technologies, such devices can offer a platform for…

With one- and two-qubit gate fidelities approaching the fault-tolerance threshold for spin qubits in silicon, how to scale up the architecture and make large arrays of spin qubits become the more pressing challenges. In a scaled-up…

What is the time-optimal way of realizing quantum operations? Here, we show how important instances of this problem can be related to the study of shortest paths on the surface of a sphere under a special metric. Specifically, we provide an…

Diamond is a promising platform for quantum information processing as it can host highly coherent qubits that could allow for the construction of large quantum registers. A prerequisite for such devices is a coherent interaction between…