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Il Nuovo Cimento A (1971-1996)

, Volume 56, Issue 3, pp 604–624 | Cite as

Exact solution of the Dirac-Pauli equation for a class of fields: Precession of polarization

  • A. Charkrabarti
Article

Summary

Exact solutions have been found, for a restricted class of plane-wave external fields, for the Dirac equation generalized through the addition of an anomalous magnetic moment and an electric dipole moment term. These solutions have been used to calculate the corresponding classical equations for the trajectory and the precession of polarization. In fact, we obtain the polarization directly in the integrated form and only subsequently verify its equation of motion. It is seen to obeyexactly the classical BMT equation proposed initially only for homogeneous fields and verified for nonhomogeneous fields only up to an approximation.

Точное решение уравнения Дирака-Пчули для некоторого класса полей: прецессия поляризации

Резюме

Для ограниченного класса плоско-волновых внешних полей были найдены точные решения для уравнения Дирака, обобщенного путем добавления аномального магнитного момента и члена электрического дипольного момента. Эти решения были использованы для определения соответствующих классических уравнений для траектории и прецессии поляризации. В действительности, мы полу-чаем поляризацию прямо в интегральной форме и затем только проверяем ее урав-нение движения. Показывается, что поляризациямочно подчиняется классичес-кому ВМТ уравнению, предположенному сначала только для однородных полей и проверенному для неоднороных полей только приближенно.

Riassunto

Si sono trovate soluzioni esatte, per una classe ristretta di campi esterni d’onde piane, per l’equazione di Dirac generalizzata mediante l’aggiunta di un momento magnetico anomalo e di un termine di momento di dipolo elettrico. Si sono adoperate queste soluzioni per calcolare le corrispondenti equazioni classiche per la traiettoria e la precessione della polarizzazione. In effetti si ottiene la polarizzazione direttamente nella forma integrata e solo successivamente si verifica la sua equazione di moto. Si osserva che essa ubbidisceesattamente all’equazione classica di BMT proposta inizialmente solo per campi omogenei e solo approssimativamente verificata per campi non omogenei.

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References

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Copyright information

© Società Italiana di Fisica 1968

Authors and Affiliations

  • A. Charkrabarti
    • 1
  1. 1.Centre de Physique Théorique de l’Ecole PolytechniqueParis

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