Il Nuovo Cimento D

, Volume 9, Issue 8, pp 1009–1032 | Cite as

Unified approach to quantum fluctuations in tunnelling including dissipation

  • A. Ranfagni
  • D. Mugnai
  • R. Englman
Article

Summary

A simple procedure for evaluating quantum fluctuations at zero temperature has been applied to derive the decay rate for a metastable state in strongly anharmonic potentials (quartic and cubic). We also derive the tunnelling splitting and the energy shift in symmetrical and nearly symmetrical double-well potentials. Dissipation is then considered for the decay of a metastable state, both in the limit of weak and strong damping.

PACS

05.40 Fluctuation phenomena, random processes and Brownian motion 

PACS

74.40 Fluctuations and critical effects 

Riassunto

Un metodo semplificato per la valutazione delle fluttuazioni quantistiche, a temperatura zero, è stato impiegato per ottenere la velocità di decadimento di uno stato metastabile in potenziali fortemente anarmonici (quartico e cubico). Si ricavano pure la separazione per tunnelling e lo spostamento di energia nel caso di potenziale a doppio pozzo, simmetrico e quasi simmetrico. Si considerano poi effetti dissipati per il decadimento di uno stato metastabile, sia nel limite di debole che di forte smorzamento.

Резюме

Простая процедура оценки квантовых флуктуаций при нулевой температуре применяется для вывода скорости распада метастабильного состояния в сильно ангармонических потенциалах (четвертого и кубичкского порядков). Мы также выводим расщепление за счет туннелирования и сдвиг энергии в потенциалах симметричной и почти симметричной двойной ямы. Затем рассматривается влияние диссипации при распаде метастабильного состояния в пределе слабого и сильного затухания.

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Copyright information

© Società Italiana di Fisica 1987

Authors and Affiliations

  • A. Ranfagni
    • 1
  • D. Mugnai
    • 1
  • R. Englman
    • 2
  1. 1.Istituto di Ricerca sulle Onde Elettromagnetiche del C.N.R.FrienzeItalia
  2. 2.Soreq Nuclear Research CenterYavneIsrael

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