「相互作用描像」の版間の差分
削除された内容 追加された内容
m stub |
m →定義: 節リンク:時間発展演算子 |
||
14行目:
<!-- To switch into the interaction picture, we divide the Schrödinger picture [[Hamiltonian (quantum mechanics)|Hamiltonian]] into two parts, <math>H_S = H_{0,S} + H_{1, S}</math>. (Any possible choice of parts will yield a valid interaction picture; but in order for the interaction picture to be useful in simplifying the analysis of a problem, the parts will typically be chosen so that <math>H_{0,S}</math> is well understood and exactly solvable, and <math>H_{1,S}</math> contains some harder-to-analyze perturbation to this system.) -->
もし、ハミルトニアンが''陽に時間に依存''する場合(例えば、量子系が時間変化する外部電場と相互作用する場合)、大抵の場合は''H<sub>1,S</sub>''に陽に時間に依る部分を含め、''H<sub>0,S</sub>''を時間非依存に選ぶのが好都合である。この場合を想定して話を進める。（もし、''H<sub>0,S</sub>''が時間依存''する''場合においては、<math>e^{\pm i H_{0,S} t/\hbar}</math>を、下に定義する、対応する[[#時間発展演算子|時間発展演算子]]に置き換えればここでの議論を適用できる。)
<!-- If the Hamiltonian has ''explicit time-dependence'' (for example, if the quantum system interacts with an applied external electric field that varies in time), it will usually be advantageous to include the explicitly time-dependent terms with <math>H_{1,S}</math>, leaving <math>H_{0,S}</math> time-independent. We will proceed assuming that this is the case. (If there ''is'' a context in which it makes sense to have <math>H_{0,S}</math> be time-dependent, then one can proceed by replacing <math>e^{\pm i H_{0,S} t/\hbar}</math> by the corresponding [[Schrödinger picture|time-evolution operator]] in the definitions below.) -->
| |||