The Behaviour of Quantum Systems in Weak Fields

姚延荪, 邹健, 邵彬

We study the quantum dynamics of a single-Cooper-pair box biased by a classical voltage and also irradiated by a single-mode quantized field.We demonstrate that under the weak damping,the collapse-revival phenomena can exist in this system.We also demonstrate that the revivals of oscillations are sensitive to the initial coherent field and the damping rate of the single-mode quantized field.

Jan Dereziński, Christian Gérard

Yao Yan-Sun, Zou Jian, Shao Bin

We study the quantum dynamics of a single-Cooper-pair box biased by a classical voltage and also irradiated by a single-mode quantized field. We demonstrate that under the weak damping, the collapse-revival phenomena can exist in this system. We also demonstrate that the revivals of oscillations are sensitive to the initial coherent field and the damping rate of the single-mode quantized field.

Xu Wei-Hua, Wu Jin-Hui, Jin-Yue Gao

We investigate the transient behaviour of a weak probe in asymmetric double quantum well structures, where two excited states are coupled by resonant tunnelling through a thin barrier in a three-level system of electronic subbands. There is no external coherent coupling field applied, and we find that probe gain can be achieved during the transient process, which is induced by the coherent coupling of the upper states via the resonant tunnelling. We show that the transient behaviour of the probe depends on the coupling strength and the dephasing rate and can be tuned by changing the width of the tunnelling barrier.

Nick Huggett, Robert Weingard