Quantum gates via continuous time quantum walks in multiqubit systems with non-local auxiliary states
| Autor: | Dmitry Solenov |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Quantum Physics Nuclear and High Energy Physics Quantum register Computer science FOS: Physical sciences General Physics and Astronomy Statistical and Nonlinear Physics Toffoli gate Topology Theoretical Computer Science 03 medical and health sciences Computer Science::Emerging Technologies 030104 developmental biology Quantum gate Computational Theory and Mathematics Quantum dot Hadamard transform Qubit Quantum walk Quantum Physics (quant-ph) Mathematical Physics Quantum computer |
| Zdroj: | Quantum Information and Computation. 17:415-455 |
| ISSN: | 1533-7146 |
| DOI: | 10.26421/qic17.5-6-4 |
| Popis: | Non-local higher-energy auxiliary states have been successfully used to entangle pairs of qubits in different quantum computing systems. Typically a longer-span non-local state or sequential application of few-qubit entangling gates are needed to produce a non-trivial multiqubit gate. In many cases a single non-local state that span over the entire system is difficult to use due to spectral crowding or impossible to have. At the same time, many multiqubit systems can naturally develop a network of multiple non-local higher-energy states that span over few qubits each. We show that continuous time quantum walks can be used to address this problem by involving multiple such states to perform local and entangling operations concurrently on many qubits. This introduces an alternative approach to multiqubit gate compression based on available physical resources. We formulate general requirements for such walks and discuss configurations of non-local auxiliary states that can emerge in quantum computing architectures based on self-assembled quantum dots, defects in diamond, and superconducting qubits, as examples. Specifically, we discuss a scalable multiqubit quantum register constructed as a single chain with nearest-neighbor interactions. We illustrate how quantum walks can be configured to perform single-, two- and three-qubit gates, including Hadamard, Control-NOT, and Toffoli gates. Continuous time quantum walks on graphs involved in these gates are investigated. Comment: 43 pages, 11 figures, with TOC |
| Databáze: | OpenAIRE |
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