Electrical Control of Interdot Electron Tunneling in a Double InGaAs Quantum-Dot Nanostructure
Electrical Control of Interdot Electron Tunneling in a Double InGaAs Quantum-Dot Nanostructure
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DOI：
10.1103/physrevlett.108.197402
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发表时间：
2012-05-08
影响因子：
8.6
通讯作者：
Finley, J. J.
中科院分区：
文献类型：
--
作者：
Mueller, K.;Bechtold, A.;Finley, J. J.
我们采用超快泵浦-探测光谱直接监测在一对空间分离的量子点中的离散轨道态之间的电子隧穿。激发后，立即在泵浦-探测光谱中观察到几个峰，这是由于光生电荷载流子之间的库仑相互作用。通过调整两个点的轨道状态的相对能量和监测的泵浦-探测光谱的时间演化的电子和空穴隧穿时间分别测量和两个点之间的共振隧穿示出介导的弹性和非弹性过程。超快（< 5 ps）的interdot隧穿发生在一个令人惊讶的宽带宽，高达类似8 meV，反映了激子声学声子耦合的系统中的频谱。
We employ ultrafast pump-probe spectroscopy to directly monitor electron tunneling between discrete orbital states in a pair of spatially separated quantum dots. Immediately after excitation, several peaks are observed in the pump-probe spectrum due to Coulomb interactions between the photogenerated charge carriers. By tuning the relative energy of the orbital states in the two dots and monitoring the temporal evolution of the pump-probe spectra the electron and hole tunneling times are separately measured and resonant tunneling between the two dots is shown to be mediated both by elastic and inelastic processes. Ultrafast (< 5 ps) interdot tunneling is shown to occur over a surprisingly wide bandwidth, up to similar to 8 meV, reflecting the spectrum of exciton-acoustic phonon coupling in the system.