In a large-scale quantum computer, the cost of communications will dominate the performance and resource requirements, place many severe demands on the technology, and constrain the architecture. Unfortunately, fault-...
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In a large-scale quantum computer, the cost of communications will dominate the performance and resource requirements, place many severe demands on the technology, and constrain the architecture. Unfortunately, fault-tolerant computers based entirely on photons with probabilistic gates, though equipped with "built-in" communication, have very large resource overheads;likewise, computers with reliable probabilistic gates between photons or quantum memories may lack sufficient communication resources in the presence of realistic optical losses. Here, we consider a compromise architecture, in which semiconductor spin qubits are coupled by bright laser pulses through nanophotonic waveguides and cavities using a combination of frequent probabilistic and sparse determinstic entanglement mechanisms. The large photonic resource requirements incurred by the use of probabilistic gates for quantum communication are mitigated in part by the potential high-speed operation of the semiconductor nanophotonic hardware. The system employs topological cluster-state quantum error correction for achieving fault-tolerance. Our results suggest that such an architecture/technology combination has the potential to scale to a system capable of attacking classically intractable computational problems.
distributed quantum computation requires that quantum operations may be acted on remote logical qubits. We investigate the possibility of the distributed quantum computation for nonlocal photons assisted by cavity qua...
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distributed quantum computation requires that quantum operations may be acted on remote logical qubits. We investigate the possibility of the distributed quantum computation for nonlocal photons assisted by cavity quantum electrodynamics. We first give a compact circuit for the controlled-NOT gate on a remote two-photon system. For the Toffoli gate, we introduce two circuits for a bipartite system with one photonic Einstein-Podolski-Rosen (EPR) entanglement. Two EPR pairs are required for a tripartite system. These Toffoli gates cost a half of entanglements required in the previous teleportation-based quantumcomputation. These elementary gates may be combined flexibly up to special decompositions of joint system in large-scale quantum applications.
We evaluate the reliability of the move operation specific to a quantumdistributed computer. We vary the noise strength for noisy operations and the fidelity of the initial EPR pair for an EPR distillation protocol. ...
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ISBN:
(纸本)9780769537825
We evaluate the reliability of the move operation specific to a quantumdistributed computer. We vary the noise strength for noisy operations and the fidelity of the initial EPR pair for an EPR distillation protocol. The noise model employed is depolarizing quantum channel. The protocol analyzed is a tradeoff between the serial purification and the tree based purification protocols - a 5 level queue protocol. Our analysis employees simulated fault injection to determine the efficiency and reliability of the purification protocol, and it uses analytical results to estimate the reliability of the operation responsible for data movement. We show that noise affecting the quantum gates acts as a limitation factor for the fidelity of the purified EPR pair independent of the number of purification levels.
A scheme for realizing the non-local Toffoli gate among three spatially separated nodes through cavity quantum electrodynamics (C-QED) is presented. The scheme can obtain high fidelity in the current C-QED system. Wit...
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A scheme for realizing the non-local Toffoli gate among three spatially separated nodes through cavity quantum electrodynamics (C-QED) is presented. The scheme can obtain high fidelity in the current C-QED system. With entangled qubits as quantum channels,
Shared entanglement allows, under certain conditions, the remote implementation of quantum operations. We revise and extend recent theoretical results on the remote control of quantum systems as well as experimental r...
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Shared entanglement allows, under certain conditions, the remote implementation of quantum operations. We revise and extend recent theoretical results on the remote control of quantum systems as well as experimental results on the remote manipulation of photonic qubits via linear optical elements.
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