论文标题
量子计算的扰动边界：数字化lambda phi^4晶格模型的实时演变
Perturbative boundaries of quantum computing: real-time evolution for digitized lambda phi^4 lattice models
论文作者
论文摘要
量子场理论模型的实时演变可以通过扰动理论中的顺序计算顺序。对于$ λϕ^4 $模型，扰动系列的收敛半径为零，部分促使数字化版本的设计适合量子计算。与一般性论点一致，表明大型场临界值改变了戴森的推理并改善了收敛性，我们表明$ λϕ^4 $晶格场理论的谐波数字化导致与有限的融合半径相结合的扩展。对于强耦合扩展，也发现了类似的收敛性。我们将数字化模型的实时演变与扰动扩展的实时演化与使用通用量子计算机所需的资源进行比较。除非可以设计出新的近似方法来有效地计算大型系统的长扰动序列，否则似乎使用具有数字化的通用量子计算机，涉及每个位置的数字化数字量具有更有效的计算中间耦合中大型系统的实时演化的可能性。
The real time evolution of quantum field theory models can be calculated order by order in perturbation theory. For $λϕ^4$ models, the perturbative series have a zero radius of convergence which in part motivated the design of digitized versions suitable for quantum computing. In agreement with general arguments suggesting that a large field cutoff modifies Dyson's reasoning and improves convergence properties, we show that the harmonic digitizations of $λϕ^4$ lattice field theories lead to weak coupling expansions with a finite radius of convergence. Similar convergence properties are found for strong coupling expansions. We compare the resources needed to calculate the real-time evolution of the digitized models with perturbative expansions to those needed to do so with universal quantum computers. Unless new approximate methods can be designed to calculate long perturbative series for large systems efficiently, it appears that the use of universal quantum computers with digitizations involving a few qubits per site has the potential for more efficient calculations of the real-time evolution for large systems at intermediate coupling.
