论文标题
键 - 键相关性，间隙关系和旋转的热力学$ 1/2 $链条带有自旋式旋转和债券订购波相
Bond-bond correlations, gap relations and thermodynamics of spin-$1/2$ chains with spin-Peierls transitions and bond-order-wave phases
论文作者
论文摘要
带有反铁磁交换的旋转$ 1/2 $链条分别在第一和第二个邻居之间的$ j_1 $和$ j_2 =αj_1$，在挫败感$ 0 \ leleα\ le 3/4 $中，同时具有间隙和间隙（$δ（$δ（$δ（$δ（α）> 0 $）量子相位。定期（$δ= 0 $）链的基态不稳定性（$δ> 0 $）以$ t_ {sp}（α）$驱动旋转旋转的过渡，该转变在这些强相关系统中随$α$而变化。相关状态的热力学极限是通过精确处理短链的精确处理，然后是逐渐更长链的密度基质重新归一化计算。差的常规相的双重变性基态是具有远距离键键相关性和电子二聚化$Δ_e（α）$的键阶波（弓）。 $ t $依赖性的$δ_e（t，α）$是使用四旋相关函数发现的，并与结构二聚化$δ（t，α）$在$ t \ le t \ le t_ {sp}（sp}（α）$形成对比。 $ t_ {sp}（α）$与$ t = 0 $ gap $δ（δ（0），α）$之间的关系在无缝隙和缝隙阶段都因沮丧而异。 $ t> t_ {sp} $以磁化易感性$χ（t，α）$可用于识别自旋Peierls系统的物理实现。 $α= 1/2 $链条说明了具有较大单元间差距和电子二聚体的常规链的特征性弓特征。
The spin-$1/2$ chain with antiferromagnetic exchange $J_1$ and $J_2 = αJ_1$ between first and second neighbors, respectively, has both gapless and gapped ($Δ(α) > 0$) quantum phases at frustration $0 \le α\le 3/4$. The ground state instability of regular ($δ= 0$) chains to dimerization ($δ> 0$) drives a spin-Peierls transition at $T_{SP}(α)$ that varies with $α$ in these strongly correlated systems. The thermodynamic limit of correlated states is obtained by exact treatment of short chains followed by density matrix renormalization calculations of progressively longer chains. The doubly degenerate ground states of the gapped regular phase are bond order waves (BOWs) with long-range bond-bond correlations and electronic dimerization $δ_e(α)$. The $T$ dependence of $δ_e(T,α)$ is found using four-spin correlation functions and contrasted to structural dimerization $δ(T,α)$ at $T \le T_{SP}(α)$. The relation between $T_{SP}(α)$ and the $T = 0$ gap $Δ(δ(0),α)$ varies with frustration in both gapless and gapped phases. The magnetic susceptibility $χ(T,α)$ at $T > T_{SP}$ can be used to identify physical realizations of spin-Peierls systems. The $α= 1/2$ chain illustrates the characteristic BOW features of a regular chain with a large singlet-triplet gap and electronic dimerization.
