论文标题
二次sachdev-ye-kitaev模型中的指数坡道
An exponential ramp in the quadratic Sachdev-Ye-Kitaev model
论文作者
论文摘要
光谱形式的长时间线性生长在中间时间提供了量子混乱的通用诊断。相比之下，尚不清楚频谱形态在无序整合多体模型中的行为。在这里，我们研究了两体Sachdev-ye-Kitaev模型，并表明光谱外形尺寸具有指数坡道，与混沌模型中的线性坡道形成鲜明对比。我们根据光谱形态的路径积分公式中的鞍点的高维歧管，找到了这种指数坡道的新机制。之所以出现这种流形，是因为该理论享有大型对称群体。凭借有限的不可整合的相互作用强度，这些精致的对称性减少了相对时间翻译，从而导致指数坡道使位于线性坡道。
A long period of linear growth in the spectral form factor provides a universal diagnostic of quantum chaos at intermediate times. By contrast, the behavior of the spectral form factor in disordered integrable many-body models is not well understood. Here we study the two-body Sachdev-Ye-Kitaev model and show that the spectral form factor features an exponential ramp, in sharp contrast to the linear ramp in chaotic models. We find a novel mechanism for this exponential ramp in terms of a high-dimensional manifold of saddle points in the path integral formulation of the spectral form factor. This manifold arises because the theory enjoys a large symmetry group. With finite nonintegrable interaction strength, these delicate symmetries reduce to a relative time translation, causing the exponential ramp to give way to a linear ramp.
