Coherence in multilevel systems

Thesis/Dissertation · Tue Jul 01 04:00:00 EDT 1975

DOI:https://doi.org/10.2172/4163453· OSTI ID:4163453

Breiland, William George ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Mathematical descriptions of an excited state multilevel system are developed to include progressively the effects of coherent coupling, feeding, decay and relaxation, and the expressions are illustrated with several pulse coherence experiments utilizing zero field optically detected magnetic resonance of excited triplet states. A new method is described in which the time development of the coherent components in a multilevel system is monitored by using an observable that can measure only relative populations between the levels. The method is illustrated. By treating a coherently driven excited state system as two levels in contact with a population reservoir, exact expressions are obtained for both transient and steady-state behavior in the presence of transverse and spin lattice relaxation, constant incoherent pumping, spontaneous emission between the two levels, and also decay back into the reservoir. The general mathematical development is applied specifically to zero field microwave phosphorescence double resonance. Experimental methods and apparatus are discussed in detail and results of optically detected transient mutations, spin echoes, and Fourier transform spectroscopy are presented.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-33-006308
• OSTI ID: 4163453
• Report Number(s): LBL--3917
• Country of Publication: United States
• Language: English

Related Subjects

*MOLECULES-- EXCITED STATES
74 ATOMIC AND MOLECULAR PHYSICS
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
SPECTRA
TRIPLETS