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Non-adiabatic effects in quantum escapes with a time-dependent potential
Non-adiabatic effects in quantum escapes of a particle via a time-dependent potential barrier in a semi-infinite one-dimensional space are discussed. We describe the time-evolution of escape states in terms of scattering states of the open system with a time-periodic potential by Floquet’s theorem a...
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Published in: | The European physical journal. B, Condensed matter physics Condensed matter physics, 2013-10, Vol.86 (10), Article 417 |
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Main Authors: | , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Non-adiabatic effects in quantum escapes of a particle via a time-dependent potential barrier in a semi-infinite one-dimensional space are discussed. We describe the time-evolution of escape states in terms of scattering states of the open system with a time-periodic potential by Floquet’s theorem and the Lippmann-Schwinger equation, and calculate concretely the probability
P
(
t
) for a particle to remain in the initially confined region at time
t
in the case of a delta-function potential with a time-oscillating magnitude. The probability
P
(
t
) decays exponentially in time at early times, then decays as a power later, along with a time-oscillation in itself. We show that a larger time-oscillation amplitude of the potential leads to a faster exponential decay of
P
(
t
), while it can rather enhance the probability
P
(
t
) decaying as a power. An explanation based on an average of adiabatic decays of
P
(
t
) is given to describe qualitatively these contrastive properties of
P
(
t
) in different types of decay. By investigating quantitative differences between the survival probability given from a direct solution of the Schrödinger equation with the time-oscillating potential and that obtained by an average of adiabatic decays, we clarify non-adiabatic effects in the decay time and the power decay magnitude of
P
(
t
). |
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ISSN: | 1434-6028 1434-6036 |
DOI: | 10.1140/epjb/e2013-40519-y |