Abstract We present a theoretical procedure, which is fundamental for unitarity preservation in multicomponent–multiband systems, for a synchronous mixed-particle quantum transport. This study focuses the problem of ( N × N ) interacting components (with N ≥ 2 ), in the framework of the envelope function approximation (EFA), and the standard unitary properties of the ( N = 1 ) scattering matrix are recovered. Rather arbitrary conditions to the basis-set and/or to the output scattering coefficients, are not longer required to preserve flux conservation, if the eigen-functions are orthonormalized in both the configuration and the spinorial spaces. We predict that the present approach, is valid for different kind of multiband–multicomponent physical systems of coupled charge–spin carriers, within the EFA, with small transformations if any. We foretell the interplay for the state-vector transfer matrix eigen-values, together with the large rates of its condition number, as novel complementary tools for a more accurate definition of the threshold for tunneling channels in a scattering experiment.

中文翻译：

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多分量散射矩阵的单一性和对称性

摘要 我们提出了一种用于同步混合粒子量子传输的理论程序，它是多分量-多波段系统中单一性保持的基础。本研究在包络函数逼近 (EFA) 的框架内关注 ( N × N ) 相互作用分量（N ≥ 2 ）的问题，并恢复了 ( N = 1 ) 散射矩阵的标准幺正性质。如果本征函数在配置和旋空间中都被正交化，则不再需要对基集和/或输出散射系数的任意条件来保持通量守恒。我们预测，本方法对于 EFA 内不同类型的耦合电荷-自旋载流子的多波段-多分量物理系统有效，如果有的话，可以进行小的转换。