论文标题
模拟多自旋量子系统的非热动力学和新兴的中央自旋模型
Simulating non-Hermitian dynamics of a multi-spin quantum system and an emergent central spin model
论文作者
论文摘要
通过将其方便地嵌入具有单一动力学的较大的希尔伯特空间的子空间中，可以模拟单个旋转$ 1/2 $（$ \ MATHSF {pt〜} $对称）系统的动力学。我们的目标是制定这种思想的许多身体概括，即嵌入许多身体非热动力学。作为朝这个方向迈出的第一步，我们调查了“ $ n $”的嵌入非相互作用旋转 - $ 1/2 $（$ \ \ \ \ Mathsf {pt〜} $对称）自由度，从而展现了这种嵌入过程的复杂性。事实证明，由此产生的Hermitian Hamiltonian代表了$ n+1 $旋转的一半群，上面有“全部”，$ q $ - 体相互作用项（$ q = 1，...，n+1 $），其中额外的旋转$ 1/2 $是较大较大嵌入空间的一部分。我们可以将其视为强烈相关的中央旋转模型，而额外的自旋$ 1/2 $扮演中央旋转的角色。我们发现，由于正交性灾难，即使是沿着中心自旋的各向异性轴施加的消失的小型交换场也会导致其强烈抑制其由自旋流失扰动引起的脱碳。
It is possible to simulate the dynamics of a single spin-$1/2$ ($\mathsf{PT~}$ symmetric) system by conveniently embedding it into a subspace of a larger Hilbert space with unitary dynamics. Our goal is to formulate a many body generalization of this idea i.e., embedding many body non-Hermitian dynamics. As a first step in this direction, we investigate embedding of "$N$" non-interacting spin-$1/2$ ($\mathsf{PT~}$ symmetric) degrees of freedom, thereby unfolding the complex nature of such an embedding procedure. It turns out that the resulting Hermitian Hamiltonian represents a cluster of $N+1$ spin halves with "all to all", $q$-body interaction terms ($q=1,...,N+1$) in which the additional spin-$1/2$ is a part of the larger embedding space. We can visualize it as a strongly correlated central spin model with the additional spin-$1/2$ playing the role of central spin. We find that due to the orthogonality catastrophe, even a vanishing small exchange field applied along the anisotropy axis of the central spin leads to a strong suppression of its decoherence arising from spin-flipping perturbations.
