基本介紹
定義,純態與混態,舉例,
定義
在量子力學當中,純態由一個相同統計系綜(ensemble)所構成,而相對於純態的混態(mixed state)則可以分解兩個以上的系綜。在量子力學中有諸多表示型(formalism),一個量子態可由密度矩陣或稱密度算符表示,區分純態和混態的方法即可由此得之。純態S可用狄拉克符號的右括向量表示:
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純態與混態
區分純態與混態的方法要利用到
。
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而兩者不同處在於
:歸一化過的純態
,而歸一化過的混態則
,和
不同,由此得以辨別出純態與混態。
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舉例
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原本純態
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