论文标题
在高阶量子绝热消除中完全违反阳性
Complete Positivity Violation in Higher-order Quantum Adiabatic Elimination
论文作者
论文摘要
当复合Lindblad系统由弱耦合的子系统组成，具有快速和缓慢的时间标准时，可以通过丢弃快速的自由度来简化对慢动力学的描述。该模型还原技术称为绝热消除。尽管相对于时间尺度分离的二阶扰动膨胀表明，降低状态的演变是完全积极的，但本文提出了一个在四阶扩展中表现出完全阳性的示例。尽管慢速动力学参数化是非唯一性的，但我们证明无法在任何参数化中确保完全阳性。违规源于初始状态的相关性。
When a composite Lindblad system consists of weakly coupled sub-systems with fast and slow timescales, the description of slow dynamics can be simplified by discarding fast degrees of freedom. This model reduction technique is called adiabatic elimination. While second-order perturbative expansion with respect to the timescale separation has revealed that the evolution of a reduced state is completely positive, this paper presents an example exhibiting complete positivity violation in the fourth-order expansion. Despite the non-uniqueness of slow dynamics parametrization, we prove that complete positivity cannot be ensured in any parametrization. The violation stems from correlation in the initial state.
