Siegert state approach to quantum defect theory

Hategan, Cornel; Ionescu, Remus Amilcar; Wolter, Hermann H. (2020): Siegert state approach to quantum defect theory. In: European Physical Journal D, Vol. 74, No. 4

Abstract

The Siegert states are approached in framework of Bloch-Lane-Robson formalism for quantum collisions. The Siegert state is not described by a pole of Wigner R-matrix but rather by the equation 1 - RnnLn = 0, relating R-matrix element R-nn to decay channel logarithmic derivative L-n. Extension of Siegert state equation to multichannel system results in the replacement of channel R- matrix element R-nn by its reduced counterpart R-nn. One proves the Siegert state is a pole, (1 - RnnLn)(-1), of multichannel collision matrix. The Siegert equation 1 - RnnLn = 0, (n - Rydberg channel), implies basic results of Quantum Defect Theory as Seaton's theorem, complex quantum defect, channel resonances and threshold continuity of averaged multichannel collision matrix elements.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 1434-6060
• Language: English