Quantum simulation of nonequilibrium dynamics and thermalization in the Schwinger model
Quantum simulation of nonequilibrium dynamics and thermalization in the Schwinger model
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DOI：
10.1103/physrevd.106.054508
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发表时间：
2021-06
影响因子：
5
通讯作者：
W. D. de Jong;Kyle Lee;J. Mulligan;M. Płoskoń;F. Ringer;Xiaojun Yao
中科院分区：
文献类型：
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作者：
W. D. de Jong;Kyle Lee;J. Mulligan;M. Płoskoń;F. Ringer;Xiaojun Yao
我们提出了在数字量子计算机上量子场理论的非平衡动力学模拟。作为一个代表性的例子，我们考虑施温格模型，一种 1+1 维 U(1) 规范理论，通过汤川型相互作用耦合到标量场理论描述的热环境。我们使用在空间晶格上离散化的施温格模型的哈密顿公式。追踪出热标量场后，施温格模型可以被视为开放量子系统，其实时动力学由马尔可夫极限下的 Lindblad 方程控制。与环境的相互作用最终促使系统达到热平衡。在量子布朗运动极限中，林德布拉德方程与场论卡尔代拉-莱格特方程相关。通过将 Stinespring 膨胀定理与辅助量子位结合使用，我们使用 IBM 模拟器和量子设备对 Schwinger 模型中的非平衡动力学和热态准备进行了研究。这里研究的场论作为开放量子系统的实时动力学和热态制备与核物理和粒子物理、量子信息和宇宙学中的各种应用相关。
We present simulations of non-equilibrium dynamics of quantum field theories on digital quantum computers. As a representative example, we consider the Schwinger model, a 1+1 dimensional U(1) gauge theory, coupled through a Yukawa-type interaction to a thermal environment described by a scalar field theory. We use the Hamiltonian formulation of the Schwinger model discretized on a spatial lattice. With the thermal scalar fields traced out, the Schwinger model can be treated as an open quantum system and its real-time dynamics are governed by a Lindblad equation in the Markovian limit. The interaction with the environment ultimately drives the system to thermal equilibrium. In the quantum Brownian motion limit, the Lindblad equation is related to a field theoretical Caldeira-Leggett equation. By using the Stinespring dilation theorem with ancillary qubits, we perform studies of both the non-equilibrium dynamics and the preparation of a thermal state in the Schwinger model using IBM’s simulator and quantum devices. The real-time dynamics of field theories as open quantum systems and the thermal state preparation studied here are relevant for a variety of applications in nuclear and particle physics, quantum information and cosmology.