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arXiv quant-ph/0612186quant-ph
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作为多体自旋1/2哈密顿量的基态的图态

Graph states as ground states of many-body spin-1/2 Hamiltonians

M. Van den Nest, K. Luttmer, W. Dür, H. J. Briegel

摘要:

考虑了图态能否成为局域相互作用哈密顿量的基态的问题。对于作用在n个量子比特上的哈密顿量,最多涉及两体相互作用,我们证明了没有n个量子比特的图形状态可以是精确的,非简并的基态。我们确定任何图形状态的最小d,使得它是d-体相互作用哈密顿量的非简并基态,而我们表明,对于d '<d的d'-体哈密顿量H,所得到的基态只能接近图形状态,代价是H相对于总能量具有小的能隙。当允许辅助粒子时,我们展示了如何利用在k-局部哈密顿问题的上下文中引入的小工具构造,以获得n-量子比特图态作为作用于n '> n自旋的两体哈密顿的非简并(准)基态。

英文摘要:

We consider the problem whether graph states can be ground states of local interaction Hamiltonians. For Hamiltonians acting on n qubits that involve at most two-body interactions, we show that no n-qubit graph state can be the exact, non-degenerate ground state. We determine for any graph state the minimal d such that it is the non-degenerate ground state of a d-body interaction Hamiltonian, while we show for d'-body Hamiltonians H with d'<d that the resulting ground state can only be close to the graph state at the cost of H having a small energy gap relative to the total energy. When allowing for ancilla particles, we show how to utilize a gadget construction introduced in the context of the k-local Hamiltonian problem, to obtain n-qubit graph states as non-degenerate (quasi-)ground states of a two-body Hamiltonian acting on n'>n spins.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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