Bertini Bruno, De Fazio Cecilia, Garrahan Juan P, Klobas Katja
School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham, NG7 2RD, United Kingdom.
Phys Rev Lett. 2024 Mar 22;132(12):120402. doi: 10.1103/PhysRevLett.132.120402.
We study the nonequilibrium dynamics of the Floquet quantum East model (a Trotterized version of the kinetically constrained quantum East spin chain) at its "deterministic point," where evolution is defined in terms of CNOT permutation gates. We solve exactly the thermalization dynamics for a broad class of initial product states by means of "space evolution." We prove: (i) the entanglement of a block of spins grows at most at one-half the maximal speed allowed by locality (i.e., half the speed of dual-unitary circuits); (ii) if the block of spins is initially prepared in a classical configuration, speed of entanglement is a quarter of the maximum; (iii) thermalization to the infinite temperature state is reached exactly in a time that scales with the size of the block.
我们研究了弗洛凯量子伊斯特模型（动力学约束量子伊斯特自旋链的一种 Trotter 化版本）在其“确定性点”的非平衡动力学，在该点，演化由 CNOT 置换门定义。我们通过“空间演化”精确求解了一大类初始积态的热化动力学。我们证明：（i）一组自旋的纠缠增长速度至多为局域性允许的最大速度的一半（即双酉电路速度的一半）；（ii）如果这组自旋最初是在经典构型中制备的，纠缠速度是最大值的四分之一；（iii）在与该组的大小成比例的时间内精确达到向无限温度态的热化。
