Fujisawa T, Oosterkamp TH, Broer BW, Aguado R, Tarucha S, Kouwenhoven LP
T. Fujisawa, Department of Applied Physics and DIMES, Delft University of Technology, 2600 GA Delft, Netherlands, and NTT Basic Research Laboratories, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa, 243-0198, Japan. T. H. Oosterkamp, W. G. van d.
Science. 1998 Oct 30;282(5390):932-5. doi: 10.1126/science.282.5390.932.
A double quantum dot device is a tunable two-level system for electronic energy states. A dc electron current was used to directly measure the rates for elastic and inelastic transitions between the two levels. For inelastic transitions, energy is exchanged with bosonic degrees of freedom in the environment. The inelastic transition rates are well described by the Einstein coefficients, relating absorption with stimulated and spontaneous emission. The most effectively coupled bosons in the specific environment of the semiconductor device used here were acoustic phonons. The experiments demonstrate the importance of vacuum fluctuations in the environment for quantum dot devices and potential design constraints for their use for preparing long-lived quantum states.
双量子点器件是一种用于电子能态的可调谐二能级系统。利用直流电子电流直接测量两个能级之间弹性和非弹性跃迁的速率。对于非弹性跃迁，能量与环境中的玻色自由度进行交换。非弹性跃迁速率可以很好地用爱因斯坦系数来描述，该系数将吸收与受激辐射和自发辐射联系起来。在这里使用的半导体器件的特定环境中，最有效地耦合的玻色子是声子。这些实验证明了环境中的真空涨落在量子点器件中的重要性以及在制备长寿命量子态时使用它们的潜在设计限制。
